cssi/SciSciGPT-SciSciNet huggingface dataset:
The Chandra High-Energy Transmission Grating Observation of an X-Ray Ionization Cone in Markarian 3

We present a preliminary analysis of the first high-resolution X-ray spectrum of a Seyfert 2 galaxy, Markarian 3, obtained with the High-Energy Transmission Grating Spectrometer on board the Chandra X-Ray Observatory. The high-energy spectrum (λ 4 A) is dominated by reflection of the active galactic nucleus continuum radiation in a cold, optically thick medium and contains bright Kα fluorescent lines from iron and silicon as well as weak, blended lines from sulfur and magnesium. The soft X-ray emission (4 A λ 23 A) is spatially extended along the [O III] ionization cone and shows discrete signatures of emission following recombination and photoexcitation produced in a warm photoionized region. The measured iron L line fluxes indicate that emission from collisionally ionized plasma is almost completely negligible and does not contribute significantly to the total energy budget of the X-ray emission. We find that significant fractions of the H- and He-like resonance lines, as well as the observed iron L lines, are produced through reemission from the warm absorbing medium observed in Seyfert 1 galaxies. Its X-ray spectral properties are qualitatively consistent with those of a typical Seyfert 1 galaxy viewed at a different orientation and provide further convincing evidence for the existence of an obscured Seyfert 1 nucleus in Mrk 3.
Characterization of a Condenser for a High Performance Multi-Condenser Loop Heat Pipe

We experimentally characterized a condenser design for a multi-condenser loop heat pipe (LHP) capable of dissipating 1000 W. The LHP is designed for integration into a high performance air-cooled heat sink to address thermal management challenges in advanced electronic systems. The multi-layer stack of condensers utilizes a sintered wick design to stabilize the liquid-vapor interface and prevent liquid flooding of the lower condenser layers in the presence of a gravitational head. In addition a liquid subcooler is incorporated to suppress vapor flashing in the liquid return line. We fabricated the condensers using photo-chemically etched Monel frames with Monel sintered wicks with particle sizes up to 44 μm. We characterized the performance of the condensers in a custom experimental flow rig that monitors the pressure and temperatures of the vapor and liquid. The condenser dissipated the required heat load with a subcooling of up to 18°C, while maintaining a stable liquid-vapor interface with a capillary pressure of 6.2 kPa. In the future, we will incorporate the condenser into a loop heat pipe for a high performance air-cooled heat sink.Copyright © 2011 by ASME
The New Horizons Spacecraft

The New Horizons spacecraft was launched on 19 January 2006. The spacecraft was designed to provide a platform for seven instruments designated by the science team to collect and return data from Pluto in 2015. The design meets the requirements established by the National Aeronautics and Space Administration (NASA) Announcement of Opportunity AO-OSS-01. The design drew on heritage from previous missions developed at The Johns Hopkins University Applied Physics Laboratory (APL) and other missions such as Ulysses. The trajectory design imposed constraints on mass and structural strength to meet the high launch acceleration consistent with meeting the AO requirement of returning data prior to the year 2020. The spacecraft subsystems were designed to meet tight resource allocations (mass and power) yet provide the necessary control and data handling finesse to support data collection and return when the one-way light time during the Pluto fly-by is 4.5 hours. Missions to the outer regions of the solar system (where the solar irradiance is 1/1000 of the level near the Earth) require a radioisotope thermoelectric generator (RTG) to supply electrical power. One RTG was available for use by New Horizons. To accommodate this constraint, the spacecraft electronics were designed to operate on approximately 200 W. The travel time to Pluto put additional demands on system reliability. Only after a flight time of approximately 10 years would the desired data be collected and returned to Earth. This represents the longest flight duration prior to the return of primary science data for any mission by NASA. The spacecraft system architecture provides sufficient redundancy to meet this requirement with a probability of mission success of greater than 0.85. The spacecraft is now on its way to Pluto, with an arrival date of 14 July 2015. Initial in-flight tests have verified that the spacecraft will meet the design requirements.
Migration of small bodies and dust to near-Earth space

Abstract The orbital evolution of Jupiter-family comets (JFCs) and asteroidal, trans-Neptunian, and cometary dust particles under the gravitational influence of planets was integrated. For dust particles, we also considered the Poynting–Robertson drag, radiation pressure, and solar wind drag. Results of our runs were compared with the spacecraft observations of the spatial density of dust particles and with the WHAM observations of velocities of zodiacal particles. This comparison shows that the fraction of cometary dust particles of the overall dust population inside Saturn’s orbit is significant and can be dominant. Our studies of migration of small bodies indicate that some former JFCs could move for millions of years inside Jupiter’s orbit and so they could produce a lot of dust. The probability of a collision of an asteroidal or cometary dust particle with the Earth during its lifetime was maximum at diameter d ∼ 100 μm. At d
Electrochemical studies of biologically-significant pterin compounds

Abstract Cyclic voltammetry has been used to study a wide variety of pterin derivatives and their redox behavior. The effect of coordinated molybdenum and tungsten on the pterin redox potentials has also been studied. Our results show that the pterins coordinated to metals appear to be good electron sources for metalloenzyme systems that require multielectron redox processes.
The Sloan Bright Arcs Survey: Ten Strong Gravitational Lensing Clusters and Evidence of Overconcentration

We describe 10 strong lensing galaxy clusters of redshift 0.26 ≤ z ≤ 0.56 that were found in the Sloan Digital Sky Survey. We present measurements of richness (N 200), mass (M 200), and velocity dispersion for the clusters. We find that in order to use the mass-richness relation from Johnston et al., which was established at mean redshift of 0.25, it is necessary to scale measured richness values up by 1.47. Using this scaling, we find richness values for these clusters to be in the range of 22 ≤ N 200 ≤ 317 and mass values to be in the range of 1 × 1014 h –1 M ☉ ≤ M 200 ≤ 30 × 1014 h –1 M ☉. We also present measurements of Einstein radius, mass, and velocity dispersion for the lensing systems. The Einstein radii (θ E ) are all relatively small, with 54 ≤ θ E ≤ 13''. Finally, we consider if there is evidence that our clusters are more concentrated than ΛCDM would predict. We find that six of our clusters do not show evidence of overconcentration, while four of our clusters do. We note a correlation between overconcentration and mass, as the four clusters showing evidence of overconcentration are all lower-mass clusters. For the four lowest mass clusters the average value of the concentration parameter c 200 is 11.6, while for the six higher-mass clusters the average value of c 200 is 4.4. ΛCDM would place c 200 between 3.4 and 5.7.
A Copulas-Based Approach to Modeling Dependence in Decision Trees

This paper presents a general framework based on copulas for modeling dependent multivariate uncertainties through the use of a decision tree. The proposed dependent decision tree model allows multiple dependent uncertainties with arbitrary marginal distributions to be represented in a decision tree with a sequence of conditional probability distributions. This general framework could be naturally applied in decision analysis and real options valuations, as well as in more general applications of dependent probability trees. While this approach to modeling dependencies can be based on several popular copula families as we illustrate, we focus on the use of the normal copula and present an efficient computational method for multivariate decision and risk analysis that can be standardized for convenient application.
Noisy-interference sum-rate capacity of parallel Gaussian interference channels

The sum-rate capacity of the parallel Gaussian interference channel is studied. Sufficient conditions are derived in terms of channel coefficients and power constraints such that the sum-rate capacity can be achieved by: 1) independent transmission across sub-channels, and 2) treating interference as noise in each sub-channel. The optimal power allocation is characterized for such parallel channels.
A simple thruput and response model of EXEC 8 under swapping saturation

EXEC 8 is the multiprogramming, time sharing operating system for the Univac 1100 computer systems. EXEC 8 attempts to provide satisfactory concurrent batch, demand (interactive), and real time processing through complicated priority scheduling schemes for both real memory and CPU time allocation. Basically, the scheduling schemes allow real time service to have whatever resources it requires and demand and batch service requests share the remainder. The sharing algorithm is quite complicated; in essence, however, it dynamically limits the time average impact of demand service on the system performance to an installation set limit function of the number of active demand users. Within the demand and batch type categories, time and core are allocated by exponential scheduling algorithms biased to favor small jobs, but constrained to service all jobs eventually. In addition, EXEC 8 provides all the I/O control, file handling, diagnostic error testing, user support systems, etc., normally associated with third generation operating systems.
Intramolecular Diels-Alder Reactions of 4H-Furo[3,4-b]indoles. New Syntheses of Benzo[a]carbazoles and Benzo[c]carbazoles

Abstract Furoindoles 7 and 16 undergo smooth intramolecular Diels-Alder reactions to afford, after dehydration, hydrolysis, and oxidation, benzocarbazoles 11 and 21, respectively.
An approach to compiler correctness

This paper is a preliminary report on an experiment in applying Floyd's method of inductive assertions to the compiler correctness problem. Practical postfix translators are considered, and the semantics of source and object languages are characterized by Floyd verification conditions. Compiler correctness proofs are partitioned into two parts. The first part deals with proofs of the syntactic and translational phase of compilation, and generates semantic equivalence theorems which are proved in the second part. These techniques are illustrated by a small example.
Hemodynamic Monitoring in Sepsis

Arterial waveform analysis that does not require continuous calibration, impedance cardiography, electrical cardiometry, velocity-encoded phase contrast magnetic resonance imaging (MRI), pulsed dye densitometry, noninvasive pulse pressure analysis using tonometry, suprasternal Doppler, partial CO2 rebreathing techniques, and transcutaneous Doppler are just some of the other emerging technologies not described in this review that may be used routinely in the management of sepsis and septic shock in the very near future. These innovative approaches may further increase our ability to optimize patients' fluid status and hemodynamics. We also have ability to monitor the microcirculation. This increasingly sophisticated approach to the management of sepsis and septic shock will hopefully translate into better patient outcomes. However, optimal use of any hemodynamic monitoring requires an understanding of its physiologic underpinnings. Accurate interpretation of the hemodynamic information coupled with a protocolized management algorithm is the cornerstone of an effective resuscitation effort. Many forms of hemodynamic monitoring have emerged over the past 20 to 30 years with no convincing evidence for the superiority of any single techniques (Table 2). The goal of hemodynamic monitoring and optimization is to combat the systemic imbalance between tissue oxygen supply and demand ranging from global tissue hypoxia to overt shock and multiorgan failure. It remains unproven that hemodynamic monitoring of disease progression can effectively change patient outcome. However, despite our increased understanding of sepsis pathophysiology, mortality and morbidity from the disease remains high. Therefore, the search for the optimal parameters in resuscitation and the best way they can be monitored will continue.
Discrete piecewise linear functions

The concept of permutograph is introduced and properties of integral functions on permutographs are investigated. The central result characterizes the class of integral functions that are representable as lattice polynomials. This result is used to establish lattice polynomial representations of piecewise linear functions on R^d and continuous selectors on linear orders.
Evaluation of the use of prophylactic cranial irradiation in small cell lung cancer

BACKGROUND: Prophylactic cranial irradiation has been used in patients with small cell lung cancer to reduce the incidence of brain metastasis after primary therapy. The purpose of this study was to evaluate the effects of prophylactic cranial irradiation (PCI) on overall survival and cause-specific survival. METHODS: A total of 7995 patients with limited stage small cell lung cancer diagnosed between 1988 and 1997 were retrospectively identified from centers participating in the National Cancer Institute's Surveillance, Epidemiology, and End Results (SEER) Program. Of them, 670 were identified as having received PCI as a component of their first course of therapy. Overall survival and cause-specific survival were estimated by the Kaplan-Meier method, comparing patients treated with or without prophylactic whole-brain radiotherapy. The Cox proportional hazards model was used in the multivariate analysis to evaluate potential prognostic factors. RESULTS: The median follow-up time was 13 months (range, 1 month to 180 months). Overall survival at 2 years, 5 years, and 10 years was 23%, 11%, and 6%, respectively, in patients who did not receive PCI. In patients who received PCI, the 2-year, 5-year, and 10-year overall survival rates were 42%, 19%, and 9%, respectively (P = <.001). The cause-specific survival rate at 2 years, 5 years, and 10 years was 28%, 15%, 11%, respectively, in patients who did not receive PCI and 45%, 24%, 17%, respectively, in patients who did receive PCI (P = <.001). On multivariate analysis of cause-specific and overall survival, age at diagnosis, sex, grade, extent of primary disease, size of disease, extent of lymph node involvement, and PCI were found to be significant (P = <.001). The hazards ratios for disease-specific and all cause mortality were 1.13 and 1.11, respectively, for those not receiving PCI. CONCLUSIONS: Significantly improved overall and cause-specific survival was observed in patients treated with prophylactic cranial irradiation on unadjusted and adjusted analyses. This study concurs with the previously published European experience. Prophylactic cranial irradiation should be considered for patients with limited stage small cell lung cancer. Cancer 2009. © 2008 American Cancer Society.
Are Optically Selected Quasars Universally X-Ray Luminous? X-Ray-UV Relations in Sloan Digital Sky Survey Quasars

We analyze archived Chandra and XMM-Newton X-ray observations of 536 Sloan Digital Sky Survey (SDSS) Data Release 5 (DR5) quasars (QSOs) at -->1.7 ≤ z≤ 2.7 in order to characterize the relative UV and X-ray spectral properties of QSOs that do not have broad UV absorption lines (BALs). We constrain the fraction of X-ray-weak, non-BAL QSOs and find that such objects are rare; for example, sources underluminous by a factor of 10 comprise 2% of optically selected SDSS QSOs. X-ray luminosities vary with respect to UV emission by a factor of 2 over several years for most sources. UV continuum reddening and the presence of narrow-line absorbing systems are not strongly associated with X-ray weakness in our sample. X-ray brightness is significantly correlated with UV emission-line properties, so that relatively X-ray-weak, non-BAL QSOs generally have weaker, blueshifted C IV λ1549 emission and broader C III] λ1909 lines. The C IV emission-line strength depends on both UV and X-ray luminosity, suggesting that the physical mechanism driving the global Baldwin effect is also associated with X-ray emission.
Variable elimination for 3D from 2D

Accurately reconstructing the 3D geometry of a scene or object observed on 2D images is a difficult problem: there are many unknowns involved (camera pose, scene structure, depth factors) and solving for all these unknowns simultaneously is computationally intensive and suffers from numerical instability. In this paper, we algebraically decouple some of the unknowns so that they can be solved for independently. Decoupling the pose from the other variables has been previously discussed in the literature. Unfortunately, pose estimation is an ill-conditioned problem. In this paper, we algebraically eliminate all the camera pose parameters (i.e., position and orientation) from the structure-from-motion equations for an internally calibrated camera. We then also fully eliminate the structure coordinates from the equations. This yields a very simple set of homogeneous polynomial equations of low degree involving only the depths of the observed points. When considering a small number of tracked points and pictures (e.g., five points on two pictures), these equations can be solved using the sparse resultant method.
Design and Potential of Non-Integrating Lentiviral Vectors

Lentiviral vectors have demonstrated promising results in clinical trials that target cells of the hematopoietic system. For these applications, they are the vectors of choice since they provide stable integration into cells that will undergo extensive expansion in vivo. Unfortunately, integration can have unintended consequences including dysregulated cell growth. Therefore, lentiviral vectors that do not integrate are predicted to have a safer profile compared to integrating vectors and should be considered for applications where transient expression is required or for sustained episomal expression such as in quiescent cells. In this review, the system for generating lentiviral vectors will be described and used to illustrate how alterations in the viral integrase or vector Long Terminal Repeats have been used to generate vectors that lack the ability to integrate. In addition to their safety advantages, these non-integrating lentiviral vectors can be used when persistent expression would have adverse consequences. Vectors are currently in development for use in vaccinations, cancer therapy, site-directed gene insertions, gene disruption strategies, and cell reprogramming. Preclinical work will be described that illustrates the potential of this unique vector system in human gene therapy.
Foreign Counterfeiting of Status Goods

We study the positive and normative effects of counterfeiting, i.e., trademark infringement, in markets where consumers are not deceived by forgeries. Consumers are willing to pay more for counterfeits than for generic merchandise of similar quality because they value the prestige associated with brand-name trademarks. Counterfeiters of status goods impose a negative externality on consumers of genuine items, as fakes degrade the status associated with a given label. But counterfeits allow consumers to unbundle the status and quality attributes of the brand-name products, and alter the competition among oligopolistic trademark owners. We analyze two policies designed to combat counterfeiting: enforcement policy which increases the likelihood of confiscation of illegal items, and the imposition of a tariff on low-quality imports.
WHO ARE THE NOISE TRADERS

Closed-end funds often trade at a discount to net asset value. Previous research suggests that the positive correlation in discounts is associated with investor sentiment that causes systematic mispricing by noise traders. We use a newly available sample of daily fund valuations to examine the relation between intraday trading activity and discount changes. Contrary to the assumption that retail investors are noise traders, we find no relation between discount changes and the order-flow imbalances of individual investors. Large daily discount changes are associated with institutional trading, and this may reflect the price inelasticity of closed-end fund shares.
Synthesis of N-aryl hydrazides by copper-catalyzed coupling of hydrazides with aryl iodides.

A convenient method for intermolecular N-arylation of hydrazides with substituted aryl iodides in the presence of a copper catalyst and Cs2CO3 is reported. The C−N coupling of N-Boc hydrazine with para- and meta-substituted aryl iodides afforded the N-arylated products A, regioselectively. A reversal in regioselectivity is observed for the arylation of benzoic hydrazide with ortho-substituted aryl iodides, providing the N‘-arylated products B.
Reducing graphics programming effort through structured support

Abstract This paper describes a method for structuring graphics support which simplifies the programming of interactive applications, while improving their portability by providing a device-independent interface. The primary objective is to ease the task of the application programmer in developing applications which use interaction and graphics. Common graphics functions which are used by several applications are generalized and defined in terms of transition tables. User actions become inputs, system wait points become states, and system responses are pointed to by table outputs. A suitable modification is applied to each of the generalized graphics functions to tailor it to be used by a particular application.
Flow equation approach to the sine-Gordon model

Abstract A continuous sequence of infinitesimal unitary transformations is used to diagonalize the quantum sine-Gordon model for β 2 ∈(2 π ,∞). This approach can be understood as an extension of perturbative scaling theory since it links weak- to strong-coupling behavior in a systematic expansion: a small expansion parameter is identified and this parameter remains small throughout the entire flow unlike the diverging running coupling constant of perturbative scaling. Our approximation consists in neglecting higher orders in this small parameter. We find very accurate results for the single-particle/hole spectrum in the strong-coupling phase and can describe the full crossover from weak to strong-coupling. The integrable structure of the sine-Gordon model is not used in our approach. Our new method should be of interest for the investigation of nonintegrable perturbations and for other strong-coupling problems.
Fuzzy control with random delays using invariant cones and its application to control of energy processes in microelectromechanical motion devices

In this paper, a class of microelectromechanical systems described by nonlinear differential equations with random delays is examined. Robust fuzzy controllers are designed to control the energy conversion processes with the ultimate objective to guarantee optimal achievable performance. The fuzzy rule base used consists of a collection of r fuzzy IF-THEN rules defined as a function of the conditional variable. The method of the theory of cones and Lyapunov functionals is used to design a class of local fuzzy control laws. A verifiably sufficient condition for stochastic stability of fuzzy stochastic microelectromechanical systems is given. As an example, we have considered the design of a fuzzy control law for an electrostatic micromotor.
Sum-free cyclic multi-bases and constructions of Ramsey algebras

Given X ? Z N , X is called a cyclic basis if ( X + X ) ? X = Z N , symmetric if x ? X implies - x ? X , and sum-free if ( X + X ) ? X = ? . We ask, for which m , N ? Z + can the set of non-identity elements of Z N be partitioned into m symmetric sum-free cyclic bases? If, in addition, we require that distinct cyclic bases interact in a certain way, we get a proper relation algebra called a Ramsey algebra. Ramsey algebras (which have also been called Monk algebras) have been constructed previously for 2 ? m ? 7 . In this manuscript, we provide constructions of Ramsey algebras for every positive integer m with 2 ? m ? 400 , with the exception of m = 8 and m = 13 .
Silica‐Gel‐Supported Ceric Ammonium Nitrate (CAN): A Simple and Efficient Solid‐Supported Reagent for Oxidation of Oxygenated Aromatic Compounds to Quinones

Abstract A silica‐gel‐supported heterogeneous ceric ammonium nitrate (CAN) reagent has been developed for oxidizing oxygenated aromatics to quinones in nonaqueous media. The advantages of this procedure include excellent yields, mild reaction conditions, nonaqueous media, short reaction times, and easy product isolation.
A Pseudorandom Generator for Polynomial Threshold Functions of Gaussian with Subpolynomial Seed Length

We develop and analyze a new family of pseudorandom generators for polynomial threshold functions with respect to the Gaussian distribution. In particular, for any fixed degree we develop a generator whose seed length is subpolynomial in the error parameter, epsilon. We get particularly nice results for degree 1 and degree 2 threshold functions, in which cases our seed length is O(log(n) + log^{3/2}(1/epsilon)) and exp(O~(log^{2/3}(1/epsilon))), respectively.
Nanoscopic filters as the origin of d-wave energy gaps

A ferroelastic nanoscopic chequerboard pattern of pseudogaps and superconductive gaps has been resolved by scanning tunnelling microscopy (STM) on Bi2Sr2CaCu2O8+ δ (BSCCO). Using this pattern, one can derive (not assume) a macroscopic anisotropic d-wave superconductive energy gap that agrees well with angle-resolved photoemission spectroscopy and Fourier transform scanning tunnelling microscopy data. The derivation is orbital only (no spins); it explains chemical trends in Raman scattering peak positions and strengths, and it predicts an unexpected reversal of anisotropic Raman gap signatures between BSCCO and La2− x Sr x CuO4 (LSCO), in good agreement with experiment.
Increased information on waterborne outbreaks through efficient notification system enforces actions towards safe drinking water

In 1997, a compulsory notification system for waterborne outbreaks was introduced in Finland. The main aim of this notification is to obtain immediate information on suspected waterborne outbreaks in order to restrict and manage the outbreak promptly. During the past ten years, there have been 67 waterborne outbreaks in Finland, mainly associated with small groundwater supplies or private wells. The number of reported waterborne outbreaks has increased since the launch of the notification system indicating that the threshold limit of outbreak detection has most probably decreased. The number of cases of illness has fulfilled the national health target, which is below 0.01% of the population, but more action is still needed to ensure the production of safe drinking water under all circumstances. Ten years accumulation of knowledge on outbreaks has revealed that a compulsory notification system is an effective tool to gather information on waterborne outbreaks. The system has also increased awareness of possible problems related to the quality of drinking water. This article summarises management and legislative actions and policy measures taken so far in Finland to reduce the number of outbreaks and cases of illness related to them.
A new solution to the solar neutrino deficit

Abstract We reexamine the transition magnetic moment solution to the solar neutrino problem. We argue that the absence of large time variations in the Super-Kamiokande rate provides strong evidence against spin-flavor flip in the solar convective zone. Spin-flavor flip could, however, occur in the primordial magnetic field in the radiative zone. We compute the longest-lived toroidal mode for this field and show that spin-flavor flip in the radiative zone can account for all available solar data.
ON A GENERALIZATION OF W -MODULES

In a recent paper of the first author and Kashyap, a new class of modules over dual operator algebras is introduced. These generalize the W � -modules (that is, Hilbert C � -modules over a von Neumann algebra which satisfy an analogue of the Riesz representation theorem for Hilbert spaces), which in turn generalize the theory of Hilbert spaces. In the present paper we give several new results about these modules. 1. Introduction and Notation
Sophisticated voting outcomes and agenda control

Necessary and sufficient conditions for an alternative to be a sophisticated voting outcome under an amendment procedure are derived. The uncovered set, as first defined by Miller (1980), is shown to be potentially reducible, and conditions are determined for which this reduction equals the set of sophisticated voting outcomes. In addition, simple methods are given for calculating both the uncovered set and its reduction.
Carijenone, a novel class of bicyclic prostanoid from the eastern Pacific octocoral Carijoa multiflora.

An unprecedented biogenetically interesting bicyclic prostanoid 1, carijenone, has been isolated from the eastern Pacific octocoral Carijoa multiflora. The C-12 oxygenated function, characteristic of the coral cyclopentanone fatty acid derivatives, is involved in the formation of a five-membered oxane ring fused to the cyclopentane network. Its structure and stereochemistry were determined on the basis of spectral studies and molecular mechanics calculations.
Determining fastest routes using fixed schedules

An interesting problem that is amenable to solution by digital computer is posed by the following questions. How late can a shipment be detained at city A so that it arrives at city B by a given time ? By what route should it be sent? The available routes consist of those provided by scheduled common carriers such as the airlines.
Cache-Friendly implementations of transitive closure

The topic of cache performance has been well studied in recent years. Compiler optimizations exist and optimizations have been done for many problems. Much of this work has focused on dense linear algebra problems. At first glance, the Floyd--Warshall algorithm appears to fall into this category. In this paper, we begin by applying two standard cache-friendly optimizations to the Floyd--Warshall algorithm and show limited performance improvements. We then discuss the unidirectional space time representation (USTR). We show analytically that the USTR can be used to reduce the amount of processor-memory traffic by a factor of O(√C), where C is the cache size, for a large class of algorithms. Since the USTR leads to a tiled implementation, we develop a tile size selection heuristic to intelligently narrow the search space for the tile size that minimizes total execution time. Using the USTR, we develop a cache-friendly implementation of the Floyd--Warshall algorithm. We show experimentally that this implementation minimizes the level-1 and level-2 cache misses and TLB misses and, therefore, exhibits the best overall performance. Using this implementation, we show a 2x improvement in performance over the best compiler optimized implementation on three different architectures. Finally, we show analytically that our implementation of the Floyd--Warshall algorithm is asymptotically optimal with respect to processor-memory traffic. We show experimental results for the Pentium III, Alpha, and MIPS R12000 machines using problem sizes between 1024 and 2048 vertices. We demonstrate improved cache performance using the Simplescalar simulator.
A review of the kinetics and mechanisms of formation of supported-nanoparticle heterogeneous catalysts

Abstract Nanoparticles supported on high surface area materials are commonly used in many industrially relevant catalytic reactions. This review examines the existing literature of the mechanisms of formation of practical, non-ultra high vacuum, supported-nanoparticle heterogeneous catalysts. Specifically, this review includes: (i) a brief overview of the synthesis of supported-nanoparticles, (ii) an overview of the physical methods for following the kinetics of formation of supported-nanoparticles, and then (iii) a summary of the kinetic and mechanistic studies of the formation of supported nanoparticle catalysts, performed under the traditional synthetic conditions of the gas–solid interface. This review then also discusses (iv) the synthesis, (v) physical methods, and (vi) the extant kinetic and mechanistic studies under the less traditional, less examined conditions of a liquid–solid system. A summary of the main insights from each section of the review is also given. Overall, surprisingly little is known about the mechanism(s) of formation of the desired size, shape and compositionally controlled supported-nanoparticle catalysts.
Hearing it From Jon Stewart: The Impact of the Daily Show on Public Attentiveness to Politics

This study examines the impact of The Daily Show with Jon Stewart, an American political comedy show, on public attentiveness to politics. I found that watching the show was positively related to following the issues that were covered with relative frequency by the program (e.g., the Afghanistan War in 2002 and news about the presidential candidates in 2004) among politically inattentive viewers. As viewers’ political attentiveness increased, however, the magnitude of the positive relationship decreased. These findings, in light of those from previous research on the show, call for further investigations of the potential effect of the program and others of its ilk on the U.S. democratic system.
Static and dynamic properties of a particle-based algorithm for non-ideal fluids and binary mixtures

A recently introduced particle-based model for fluid dynamics with effective excluded volume interactions is analysed in detail. The interactions are modelled by means of stochastic multiparticle collisions which are biased and depend on local velocities and densities. The model is Galilean-invariant; momentum and energy are exactly conserved locally. The isotropy and relaxation to equilibrium are analysed and measured. It is shown how a discrete-time projection operator technique can be used to obtain Green-Kubo relations for the transport coefficients. Because of a large viscosity no long-time tails in the velocity auto-correlation and stress correlation functions were seen. Strongly reduced self-diffusion due to caging and an order/disorder transition are found at high collision frequencies, where clouds consisting of at least four particles form a cubic phase. These structures were analysed by measuring the pair-correlation function above and below the transition. Finally, the algorithm is extended to binary mixtures which phase-separate above a critical collision rate.
Synthesis of a Functionalized Allylic Phosphine Oxide

Abstract A functionalized allylic phosphine oxide has been prepared by regioselective bromination of 2-(methyldiphenylphosphinoyl)-1-propene followed by nucleophilic substitution with acetate. Hydrolysis and protection yielded the target compound.
Emission line ratios and variations in temperature and ionization state in the diffuse ionized gas of five edge-on galaxies

We present spectroscopic observations of ionized gas in the disk-halo regions of five edge-on galaxies, covering a wavelength range from [O II] 3727 A to [S II] 6716.4 A. The inclusion of the [O II] emission provides additional constraints on the properties of the diffuse ionized gas (DIG), in particular, the origin of the observed spatial variations in the line intensity ratios. We have derived electron temperatures, ionization fractions, and abundances along the slit. Our data include slit positions both parallel and perpendicular to the galactic disks. This allowed us to examine variations in the line intensity ratios with height above the midplane, as well as with distance from the galactic centers. The observed increase in the [O II]/Hα line ratio toward the halo seems to require an increase in electron temperature caused by a nonionizing heating mechanism. We conclude that gradients in the electron temperature can play a significant role in the observed variations in the optical emission-line ratios from extraplanar DIG.
The “Gulliver effect” and the “optimal divergence” approach to trade policies: The case of nepal

Abstract A country could be small in the world economy yet become big in relation to its smaller neighbors, imposing on them its relative price structure and the consequences of its trade policies. We examine here the consequences of such a “Gulliver” effect, looking at the case of Nepal whose economy is closely linked to the economy of India. Since India's protective policies are not optimal for Nepal, we consider the various alternatives for Nepal. The “optimal divergence” is for Nepal to allow the free import of intermediate and capital goods, while, for import-competing industries, it cannot depart from India's trade policy.
Canaries in a coal mine: using globular clusters to place limits on massive black holes in the galactic halo

We explore the possibility that massive black holes comprise a significant fraction of the dark matter of our Galaxy by studying the dissolution of Galactic globular clusters bombarded by them. In our simulations, we evolve the clusters along a sequence of King models determined by changes of state resulting from collisions with the black holes. We include mass loss in collisions as well as the heating of the remaining bound stars, and determine the role that a finite number of stars plays in the variance of the energy input and mass loss. Several methods are used to determine the range of black hole masses and abundances excluded by survival of Galactic globular clusters: simple order-of-magnitude estimates; collision-by-collision simulations of the energy input and mass loss of a stellar cluster; and a ‘smoothed’ Monte Carlo calculation of the evolution of cluster energy and mass. The results divide naturally into regimes of ‘small’ and ‘large’ black hole mass. ‘Small’ black holes do not destroy clusters in single collisions; their effect is primarily cumulative, leading to a relation between Mbh and fhalo, the fraction of the halo in black holes of mass Mbh, which is fhalo Mbh< constant (up to logarithmic corrections). For fhalo=1, we find Mbh∼ 103 M⊙ by requiring survival of the same clusters studied by Moore, who neglected cluster evolution, mass loss, and stochasticity of energy inputs in his estimates, but reached a similar conclusion. ‘Large’ black holes may not penetrate a cluster without disrupting it; their effect is mainly catastrophic (close collisions), but also partly cumulative (distant collisions). In the large- Mbh limit, fhalo (but not Mbh) can be constrained by computing the probability that a cluster survives a combination of close, destructive encounters and distant, non-destructive encounters. We find that it is unlikely that fhalo∼ 0.3 by requiring 50 per cent survival probability for Moore’s clusters over 1010 yr.
Dynamic intrusion detection in resource-constrained cyber networks

We consider a large-scale cyber network with N components. Each component is either in a healthy state (0) or an abnormal state (1). Due to intrusions, the state of each component transits from 0 to 1 over time according to an arbitrary stochastic process. At each time, a subset of K (K < N) components are probed and those observed in abnormal states are fixed. The objective is to design a dynamic probing strategy that minimizes the long-term network cost incurred at all abnormal components. We formulate the problem as a Restless Multi-Armed Bandit (RMAB) process. We show that this class of RMAB is indexable and Whittle index can be obtained in closed-form. For homogeneous networks, we show that Whittle index policy achieves the optimal performance with a simple structure that does not require any prior knowledge on the intrusion processes.
The spanwise lift distribution on a wing from flow-field velocity surveys

The application of the incompressible three-dimensional momentum integral equation to a finite wing is reviewed. The objective is to interpret the resulting equations in a way that suggests an alternate experimental method for determining the span-wise distribution of lift. Consideration is given to constraints that must be placed on the character of the vortex wake of the wing to provide the familiar relationship between lift and bound vorticity. A novel technique is then presented for obtaining, from behind the wing, the spanwise lift distribution from velocity surveys that are made over only a short distance above and below the wing trailing edge. The necessary formalism is developed to use these measured values to obtain the actual span loading by using an equivalent single horseshoe vortex model to account for the unmeasured portion of the downward (or upward) momentum. The results of a numerical simulation are presented for a typical loading distribution. The technique is then verified experimentally using laser velocimeter data for the flow field around a model wing.
A pp-wave with 26 supercharges

A pp-wave solution to 11-dimensional supergravity is given with precisely 26 supercharges. Its uniqueness and the absence of 11-dimensional pp-waves which preserve (precisely) 28 or 30 supercharges is discussed. Compactification on a spacelike circle gives a IIA configuration with all 26 of the supercharges. For this compactification, the D0 brane charge does not appear in the supersymmetry algebra. Indeed, the 26 supercharge IIA background does not admit any supersymmetric D-branes. In the appendix, a 28 supercharge IIB pp-wave is presented along with its supersymmetry algebra.
Neural Network Based Temperature-Dependent Quantitative Structure Property Relations (QSPRs) for Predicting Vapor Pressure of Hydrocarbons

A neural network based quantitative structure−property relationship (QSPR) was developed for the vapor pressure−temperature behavior of hydrocarbons based on a data set for 274 compounds. The optimal QSPR model was developed based on a 7-29-1 back-propagation neural network architecture using valance molecular connectivity indices (1χv, 3χv, 4χv), molecular weight, and temperature as input parameters. The average absolute errors in vapor pressure predictions for the test, validation, and overall data sets were 8.2% (0.036 log P units or 23.2 kPA), 9.2% (0.039 log P units or 26.8 kPA), and 10.7% (0.046 log P units or 31.1 kPA), respectively. The performance of the QSPR for temperature-dependent vapor pressure, which was developed from a simple set of molecular descriptors, displayed accuracy of better than or well within the range of other available estimation methods.
The Stability of Magnetized Rotating Plasmas with Superthermal Fields

During the last decade it has become evident that the magnetorotational instability is at the heart of the enhanced angular momentum transport in weakly magnetized accretion disks around neutron stars and black holes. In this paper we investigate the local linear stability of differentially rotating, magnetized flows and the evolution of the magnetorotational instability beyond the weak-field limit. We show that, when superthermal toroidal fields are considered, the effects of both compressibility and magnetic tension forces, which are related to the curvature of toroidal field lines, should be taken fully into account. We demonstrate that the presence of a strong toroidal component in the magnetic field plays a nontrivial role. When strong fields are considered, the strength of the toroidal magnetic field not only modifies the growth rates of the unstable modes but also determines which modes are subject to instabilities. We find that, for rotating configurations with Keplerian laws, the magnetorotational instability is stabilized at low wavenumbers for toroidal Alfven speeds exceeding the geometric mean of the sound speed and the rotational speed. For a broad range of magnetic field strengths, we also find that two additional distinct instabilities are present; they both appear as the result of coupling between the modes that become the Alfven and the slow modes in the limit of no rotation. We discuss the significance of our findings for the stability of cold, magnetically dominated, rotating fluids and argue that, for these systems, the curvature of toroidal field lines cannot be neglected even when short-wavelength perturbations are considered. We also comment on the implications of our results for the validity of shearing box simulations in which superthermal toroidal fields are generated.
The reaction NH2 + PH3 yields NH3 + PH2 - Absolute rate constant measurement and implication for NH3 and PH3 photochemistry in the atmosphere of Jupiter

The rate constant is measured over the temperature interval 218-456 K using the technique of flash photolysis-laser-induced fluorescence. NH2 radicals are produced by the flash photolysis of ammonia highly diluted in argon, and the decay of fluorescent NH2 photons is measured by multiscaling techniques. For each of the five temperatures employed in the study, the results are shown to be independent of variations in PH3 concentration, total pressure (argon), and flash intensity. It is found that the rate constant results are best represented for T between 218 and 456 K by the expression k = (1.52 + or - 0.16) x 10 to the -12th exp(-928 + or - 56/T) cu cm per molecule per sec; the error quoted is 1 standard deviation. This is the first determination of the rate constant for the reaction NH2 + PH3. The data are compared with an estimate made in order to explain results of the radiolysis of NH3-PH3 mixtures. The Arrhenius parameters determined here for NH2 + PH3 are then constrasted with those for the corresponding reactions of H and OH with PH3.
Improved Syntheses of 5‐Hydroxy‐2‐Pyridones (2,5‐Dihydroxypyridines)

Improved syntheses of 5-hydroxy-2-pyridone, 6-chloro-5-hydroxy-2-pyridone, 2,5-dihydroxynicotinic acid, and three methyl-substituted 5-hydroxy-2-pyridones are reported.
An overview of geological results from Mariner 9

A summary of Mariner 9 mission operations insofar as they affected acquisition of geologic data is reported. Selected results with a minimum of supporting evidence are presented to give the geologic highlights of the mission. Volcanic features, tectonic features, channels, polar features, eolian features, impact craters, and the geological history of Mars are outlined.
Using Geoelectrons to Search for Velocity-Dependent Spin-Spin Interactions

We use the recently developed model of the electron spins within Earth to investigate all of the six possible long-range velocity-dependent spin-spin interactions associated with the exchange of an ultralight (${m}_{{z}^{\ensuremath{'}}}l{10}^{\ensuremath{-}10}\text{ }\text{ }\text{eV}$) or massless intermediate vector boson. Several laboratory experiments have established upper limits on the energy associated with various fermion-spin orientations relative to Earth. We combine the results from three of these experiments with the geoelectron-spin model to obtain bounds on the velocity-dependent interactions that couple electron spin to the spins of electrons, neutrons, and protons. Five of the six possible potentials investigated were previously unbounded. In the long-range limit we have improved the bound on the sixth potential by 30 orders of magnitude.