cssi/SciSciGPT-SciSciNet huggingface dataset:
THE COMPACT CENTRAL OBJECT IN THE SUPERNOVA REMNANT G266.2 1.2

We observed the compact central object CXOU J085201.4-461753 in the supernova remnant G266.2-1.2 (RX J0852.0-4622) with the Chandra ACIS detector in timing mode. The spectrum of this object can be described by a blackbody model with the temperature kT = 404 ± 5 eV and radius of the emitting region R = 0.28 ± 0.01 km at a distance of 1 kpc. Power-law and thermal plasma models do not fit the source spectrum. The spectrum shows a marginally significant feature at 1.68 keV. A search for periodicity yields two candidate periods, about 301 and 33 ms, both significant at a 2.1 σ level; the corresponding pulsed fractions are 13% and 9%, respectively. We find no evidence for long-term variability of the source flux, nor do we find extended emission around the central object. We suggest that CXOU J085201.4-461753 is similar to CXOU J232327.9+584842, the central source of the supernova remnant Cas A. It could be either a neutron star with a low or regular magnetic field, slowly accreting from a fossil disk or, more likely, an isolated neutron star with a superstrong magnetic field. In either case, a conservative upper limit on surface temperature of a 10 km radius neutron star is about 90 eV, which suggests accelerated cooling for a reasonable age of a few thousand years.
Efficiency audit: An assembly of rationalities and programmes

Abstract This paper focuses on the insertion of accounting and auditing knowledge into wider areas of practice, and examines the processes of auditing change through studying the development of “efficiency auditing” using events in one jurisdiction, the Province of Alberta, Canada, as an exemplar. These developments are interpreted through use of Miller and Rose's (1990; Rose & Miller, 1992) theoretical concerns with governmentality, and especially the links between generally stated political rationalities and more specific programmes for action. In studying the association of ideas of efficiency with auditing, and the developing belief that efficiency could be investigated or procured through audit scrutiny, it is argued that these events can be understood in terms of an intersection between wider discourse (concerning, for example, best management practice, appropriate auditing roles, etc.) and local circumstance. The specific interpretations that result are understood as providing one set of conditions by which auditing (and accounting are linked to the social (Burchell et al., 1985). Further research (Radcliffe, 1995) attends to the logistics of how one might audit for efficiency, using fieldwork to trace the technologies which provide practitioners with particular mechanisms for action (Miller & Rose, 1990). © 1998 Elsevier Science Ltd. All rights reserved.
Pre-Stall Instability Distribution Over a Transonic Compressor Rotor

An investigation of the behavior of a transonic compressor rotor when operating close to stall is presented. The specific areas of interest are the behavior and location of low-frequency instabilities close to stall. In running close to stall, compressors can begin to exhibit nonperiodic flow between the blade passages even when appearing to be operating in a stable steady-state condition. The data from the current rotor clearly show that low-frequency instabilities were present during steady-state operation when stall was approached. These frequencies are not geometrically fixed to the rotor and typically appear at 0.3―0.8 of the rotor speed. The presence of these low-frequency instabilities is known and detection is reasonably commonplace; however, attempts to quantify the location and strength of these instabilities as stall is approached have proved difficult. In the current test fast response pressure sensors were positioned in the case-wall; up-stream, downstream, and over the rotor blade tips. Simultaneous data from the sensors were taken at successive steady-state settings with each being closer to stall. A time domain analysis of the data investigates the magnitude of the instabilities and their transient effect on the relative inlet flow angle. The data are also presented in the frequency domain to show the development and distribution of the instabilities over the rotor as stall was approached. Initially the instabilities appeared within the rotor row and extended downstream but at operation closer to stall they began to protrude upstream as well. The greatest amplitude of the instabilities was within the blade row in the complex flow region that contains phenomena such as the tip-vortex/normal-shock interaction and the shock/boundary-layer interaction. In addition as stall is approached the growth of the instabilities is nonlinear and not confined to one frequency.
A Rapid Divergent Synthesis of Highly Substituted δ-Lactones

Nucleophilic 1,2-addition of (Z)-γ-silyloxyvinylzinc reagents to ethyl glyoxylate followed by desilylation and cyclization affords 3,6-dihydro-3-hydroxypyran-2-ones in good chemical yields. In situ formation of allylic phosphates followed by reaction with RCu(CN)Li reagents affords substituted 5,6-dihydropyran-2-ones. The parent compound, 3,6-dihydro-3-hydroxypyran-2-one, undergoes allylic phosphate formation, cuprate-mediated allylic substitution, and 1,4-conjugate addition to afford trans-4,5-disubstituted tetrahydropyran-2-ones in a one-pot process.
APPLICATION PLACEMENT ON A CLUSTER OF SERVERS

The APPLICATION PLACEMENT PROBLEM (APP, for short) arises in hosting platforms: clusters of servers that are used for hosting large, distributed applications such as Internet services. Hosting platforms imply a business relationship between an entity called the platform provider and a number of entities called the application providers. The latter pay the former for the resources on the hosting platform, in return for which, the former provides guarantees on resource availability for the applications. This implies that a hosting platform should host only applications for which it has sufficient resources. The objective of the APP is to maximize the number of applications that can be hosted on the platform while satisfying their resource requirements. The complexity of the APP is studied here, with the following results. The general APP is NP-hard; indeed, even restricted versions of the APP may not admit polynomial-time approximation schemes. However, several significant variants of the online version of the APP admit efficient approximation algorithms.
The human oxygen sensing machinery and its manipulation

Animals respond to the challenge of limited oxygen availability by a coordinated response that works to increase oxygen supply and minimize tissue damage. The chronic hypoxic response is mediated by the α,β-hypoxia inducible transcription factor (HIF) that enables the expression of a gene array. Because this array includes genes encoding for proteins that regulate processes including red blood cell and blood vessel formation, manipulation of the HIF system has potential for the treatment of ischemic diseases, anaemia and tumours. Hydroxylase enzymes act as oxygen sensors by regulating both the lifetime of HIF-α and its transcriptional activity. This tutorial review aims to provide a non-expert introduction to the HIF field by providing a background to current work, summarising molecular knowledge on the HIF system, and outlining opportunities for therapeutic intervention.
Microwave spectrum and structure of the conformers of 3,3-difluoroacryloyl fluoride

Abstract The microwave spectra of the syn and anti conformers of difluoroacryloyl fluoride have been assigned and analyzed. Ab initio computations place the syn form lower in energy by 132 cal mol −1 , while the experimental data place the value at 170±100 cal mol −1 . Investigations of the molecular structure with both experimental and microwave data show significant geometry changes upon syn-anti isomerization. The relative conformer energies and geometries show a consistent behavior when compared to acryloyl fluoride.
A File Is Not a File: Understanding the I/O Behavior of Apple Desktop Applications

We analyze the I/O behavior of iBench, a new collection of productivity and multimedia application workloads. Our analysis reveals a number of differences between iBench and typical file-system workload studies, including the complex organization of modern files, the lack of pure sequential access, the influence of underlying frameworks on I/O patterns, the widespread use of file synchronization and atomic operations, and the prevalence of threads. Our results have strong ramifications for the design of next generation local and cloud-based storage systems.
Critical alignments in plane mirror interferometry

Abstract Each axis of a plane mirror interferometer has three associated measurement vectors: the interferometer beam, mirror normal, and axis of measurement. The transducer axis of a plane mirror interferometer target is the mirror normal. This contrasts with a retroflector for which the transducer axis is the interferometer beam. The classical cosine error in x-y plane mirror interferometry is removed by the orienting the mirror normals in the travel plane. The axes do not have to be orthogonal to eliminate cosine error.
Green Bank Telescope Observations of Interstellar Glycolaldehyde: Low-Temperature Sugar

Interstellar glycolaldehyde (CH20HCHO) has been detected with the 100-m Green Bank Telescope (GBT) toward the star-forming region Sagittarius B2(N) by means of the 1(sub 10)-1(sub 01),2(sub 11)-2(sub 02),3(sub 12)-3(sub 0), and 4(sub 13)-4(sub 04) rotational transitions at 13.48, 15.18, 17.98, and 22.14 GHz, respectively. An analysis of these four high signal- to-noise rotational transitions yields a glycolaldehyde state temperature of ~8 K. Previously reported emission line detections of glycolaldehyde with the NRAO 12-m telescope at mm-wavelengths (71 GHz to 103 GHz) are characterized by a state temperature of -50 K. By comparison the GBT detections are surprisingly strong and seen in emission at 13.48 GHz, emission and absorption at 15.18 GHz, and absorption at 17.98 GHz and 22.14 GHz. We attribute the strong absorption observed by the GBT at the higher frequencies to the correspondingly smaller GBT beams coupling better to the continuum source(s) in Sagittarius B2(N). A possible model for the two-temperature regions of glycolaldehyde is discussed.
Foreign exchange volatility and international pricing

This paper explores the hypothesis that the unresponsiveness of export pricing to exchange rate fluctuations may be partially the result of hedging activities by trading agents due to foreign exchange volatility (EV) to eliminate exchange risk. In essence, hedging against foreign exchange uncertainty affects the structure of pass-through relationship. The exchange rate pass-through issue is governed by a firm-specific factor like hedging, in addition to market share, product differentiation and market structure. A reduction in exchange risk exposure leads to a decline in the willingness rather than the ability to pass the cost shock to consumers. The estimation of foreign EV dummy interacting with one-year-lagged exchange rate on export pricing supports the hypothesis that there is a significant differential impact of high- and low-EV destinations on the degree of pass-through which, in turn, affects international pricing.
Characterizing Honeypot-Captured Cyber Attacks: Statistical Framework and Case Study

Rigorously characterizing the statistical properties of cyber attacks is an important problem. In this paper, we propose the first statistical framework for rigorously analyzing honeypot-captured cyber attack data. The framework is built on the novel concept of stochastic cyber attack process, a new kind of mathematical objects for describing cyber attacks. To demonstrate use of the framework, we apply it to analyze a low-interaction honeypot dataset, while noting that the framework can be equally applied to analyze high-interaction honeypot data that contains richer information about the attacks. The case study finds, for the first time, that long-range dependence (LRD) is exhibited by honeypot-captured cyber attacks. The case study confirms that by exploiting the statistical properties (LRD in this case), it is feasible to predict cyber attacks (at least in terms of attack rate) with good accuracy. This kind of prediction capability would provide sufficient early-warning time for defenders to adjust their defense configurations or resource allocations. The idea of “gray-box” (rather than “black-box”) prediction is central to the utility of the statistical framework, and represents a significant step towards ultimately understanding (the degree of) the predictability of cyber attacks.
Synthesis of 2,6-disubstituted dihydropyrans via an efficient BiBr3-initiated three component, one-pot cascade

The rapid synthesis of cis-2,6-disubstituted dihydropyrans is achieved in a three-component, one-pot cascade reaction. BiBr(3)-ediated addition of ketene silyl acetals or silyl enol ethers to beta,gamma-unsaturated cis-4-trimethylsilyl-3-butenal provides a Mukaiyama aldol adduct containing a vinylsilane moiety tethered to a silyl ether. Addition of a second aldehyde initiates a domino sequence involving intermolecular addition followed by an intramolecular silyl-modified Sakurai (ISMS) reaction. Isolated yields of this one-pot reaction vary from 44 to 80% and all compounds were isolated as the cis-diastereomers (10 examples).
Radioisotope electric propulsion missions utilizing a common spacecraft design

Abstract A study was conducted that shows how a single radioisotope electric propulsion (REP) spacecraft design could be used for various missions throughout the solar system. This spacecraft design is based on an REP feasibility design from a study performed by NASA Glenn Research Center and the Johns Hopkins University Applied Physics Laboratory. The study also identifies technologies that need development to enable these missions. The mission baseline for the REP feasibility design study is a Trojan asteroid orbiter. This mission sends an REP spacecraft to Jupiter's leading Lagrange point where it would orbit and examine several Trojan asteroids. The spacecraft design from the REP feasibility study would also be applicable to missions to the Centaurs, and through some change of payload configuration could accommodate a comet sample-return mission. Missions to small bodies throughout the outer solar system are also within reach of this spacecraft design. This set of missions, utilizing the common REP spacecraft design, is examined, and required design modifications for specific missions are outlined.
High-Resolution Measurements of the Dark Matter Halo of NGC 2976: Evidence for a Shallow Density Profile*

We have obtained two-dimensional velocity fields of the dwarf spiral galaxy NGC 2976 in H? and CO. The high spatial (~75 pc) and spectral (13 and 2 km?s-1, respectively) resolution of these observations, along with our multicolor optical and near-infrared imaging, allows us to measure the shape of the density profile of the dark matter halo with good precision. We find that the total (baryonic plus dark matter) mass distribution of NGC 2976 follows a ?tot r-0.27?0.09 power law out to a radius of 1.8 kpc, assuming that the observed radial motions provide no support. The density profile attributed to the dark halo is even shallower, consistent with a nearly constant density of dark matter over the entire observed region. A maximal disk fit yields an upper limit to the K-band stellar mass-to-light ratio (M*/LK) of 0.09 M?/L?K (including systematic uncertainties), with the caveat that for M*/LK > 0.19 M?/L?K the dark matter density increases with radius, which is unphysical. Assuming 0.10 M?/L?K M*/LK ? 0.19 M?/L?K, the dark matter density profile lies between ?DM r-0.17 and ?DM r-0.01. Therefore, independent of any assumptions about the stellar disk or the functional form of the density profile, NGC 2976 does not contain a cuspy dark matter halo. We also investigate some of the systematic effects that can hamper rotation curve studies and show that (1) long-slit rotation curves are far more vulnerable to systematic errors than two-dimensional velocity fields, (2) NGC 2976 contains radial motions that are as large as 90% of the rotational velocities at small radii, and (3) the H? and CO velocity fields of NGC 2976 agree within their uncertainties, with a typical scatter between the two velocities of 5.3 km s-1 at any position in the galaxy.
Synthesis of the core ring system of the sclerophytin diterpenes utilizing a Lewis acid-promoted [4+3] annulation strategy

The synthesis of the core ring system of the sclerophytin diterpenes is described. The key tetrahydrofuran-containing intermediate is assembled via a Lewis acid-promoted [4+3] annulation reaction between a mixed dimethyl acetal and a bis-TES dienol ether. The resulting β-keto ester was homologated, cyclized, and ring expanded to afford the sclerophytin ring system.
Rotational Quasi-Periodicities and the Sun – Heliosphere Connection

Mutual quasi-periodicities near the solar-rotation period appear in time series based on the Earth’s magnetic field, the interplanetary magnetic field, and signed solar-magnetic fields. Dominant among these is one at 27.03±0.02 days that has been highlighted by Neugebauer et al. (J. Geophys. Res.105, 2315, 2000). Extension of their study in time and to different data reveals decadal epochs during which the ≈ 27.0 days, or a ≈ 28.3 days, or other quasi-periods dominate the signal. Space-time eigenvalue analyses of time series in 30 solar latitude bands, based on synoptic maps of unsigned photospheric fields, lead to two maximally independent modes that account for almost 30% of the data variance. One mode spans 45° of latitude in the northern hemisphere and the other one in the southern. The modes rotate around the Sun rigidly, not differentially, suggesting connection with the subsurface dynamo. Spectral analyses yield familiar dominant quasi-periods 27.04±0.03 days in the North and at 28.24±0.03 days in the South. These are replaced during cycle 23 by one at 26.45±0.03 days in the North. The modes show no tendency for preferred longitudes separated by ≈ 180°.
DETECTING THE WIND-DRIVEN SHAPES OF EXTRASOLAR GIANT PLANETS FROM TRANSIT PHOTOMETRY

Several processes can cause the shape of an extrasolar giant planet's shadow, as viewed in transit, to depart from circular. In addition to rotational effects, cloud formation, non-homogenous haze production and movement, and dynamical effects (winds) could also be important. When such a planet transits its host star as seen from the Earth, the asphericity will introduce a deviation in the transit light curve relative to the transit of a perfectly spherical (or perfectly oblate) planet. We develop a theoretical framework to interpret planetary shapes. We then generate predictions for transiting planet shapes based on a published theoretical dynamical model of HD189733b. Using these shape models we show that planet shapes are unlikely to introduce detectable light-curve deviations (those >1 × 10–5 of the host star), but that the shapes may lead to astrophysical sources of systematic error when measuring planetary oblateness, transit time, and impact parameter.
Enantioselective synthesis of nitroalkanes bearing all-carbon quaternary stereogenic centers through Cu-catalyzed asymmetric conjugate additions.

The first examples of catalytic asymmetric conjugate addition (ACA) of alkylzinc reagents to trisubstituted nitroalkenes, leading to the formation of nitroalkanes bearing a quaternary carbon stereogenic center, are reported. Reactions are promoted in the presence of 4 mol % of a readily available amino acid-based phosphine and 2 mol % (CuOTf)·C6H6. Cu-catalyzed reactions proceed efficiently in up to 98% ee and can be carried out with a variety of dialkylzinc reagents and trisubstituted nitroolefins. We highlight the synthetic utility of the products obtained by efficient conversion of optically enriched nitroalkanes to the corresponding carboxylic acids.
Fine Separation of Average-Time Complexity Classes

We extend Levin's definition of average polynomial time to arbitrary time-bounds in accordance with the following general principles: (1) It essentially agrees with Levin's notion when applied to polynomial time-bounds. (2) If a language L belongs to DTIME(T(n)) for some time-bound T(n), then every distributional problem $(L,\mu)$ is T on the $\mu$-average. (3) If L does not belong to DTIME(T(n)) almost everywhere, then no distributional problem $(L,\mu)$ is T on the $\mu$-average. We present hierarchy theorems for average-case complexity, for arbitrary time-bounds, that are as tight as the well-known Hartmanis--Stearns hierarchy theorem for deterministic complexity. As a consequence, for every time-bound T(n), there are distributional problems $(L,\mu)$ that can be solved using only a slight increase in time but that cannot be solved on the $\mu$-average in time T(n).
Intelligent Videodisc and the Learning Society.

Discoveries of fundamental importance are occurring in all areas of science at an incredible rate. However, continued growth and exploitation of information rests not only on science's ability to produce new knowledge but also upon society's ability to learn and to apply knowledge in a productive way. If we are to continue to reap the advantages of the “information explosion,” we need new, powerful intellectual tools to augment and expand human capacity to reason and to work “smarter.” The National Science Foundation has initiated a research and development thrust for a proof-of-concept demonstration of an intelligent videodisc system for science education in the hope that it will stimulate others to seek new instructional paradigms and to explore new technological innovations for use in the learning society.
Microdunes and other aeolian bedforms on Venus: Wind tunnel simulations

The development of aeolian bedforms in the simulated Venusian environment has been experimentally studied in the Venus Wind Tunnel. It is found that the development of specific bedforms, including ripples, dunes, and 'waves', as well as their geometry, are controlled by a combination of factors including particle size, wind speed, and atmospheric density. Microdunes are formed which are analogous to full-size terrestrial dunes and are characterized by the development of slip faces, internal cross-bedding, a low ratio of saltation path length to dune length, and a lack of particle-size sorting. They begin to develop at wind speeds just above saltation threshold and evolve into waves at higher velocities. At wind speeds of about 1.5 m/sec and higher, the bed is flat and featureless. This evolution is explained by a model based on the interaction of alternating zones of erosion and deposition and particle saltation distances.
The Impact of Positive and Negative Affect and Issue Framing on Issue Interpretation and Risk Taking.

Abstract Two studies examined the influence of transient affective states and issue framing onissue interpretationandrisk takingwithin the context of strategic decision making. In Study 1, participants in whom transient positive or negative affective states were induced by reading a short story showed systematic differences in issue interpretation and risk taking in a strategic decision making context. Compared to negative mood participants, those in a positive mood were more likely to interpret the strategic issue as an opportunity and displayed lower levels of risk taking. Study 2 replicated and extended these results by crossing affective states with threat and opportunity frames. Results showed that framing an issue (as a threat or an opportunity) had a stronger impact on issue interpretation among negative affect participants than among positive affect participants. Affective states also moderated the impact of issue framing on risk taking: the effect of framing on risk-taking was stronger under negative rather than positive affect. These results are interpreted via information-processing and motivational effects of affect on a decision maker.
Analysis of hydrogeological structure uncertainty by estimation of hydrogeological acceptance probability of geostatistical models

Abstract The following describes a proposed approach to account for the equifinality of solutions that result from comparing observations to flow simulations when using realizations of geostatistical models. We introduce hydrogeological acceptance probability to estimate the propensity of a geostatistical model to produce acceptable realizations with respect to the consistency of their simulations with observations. The estimation of hydrogeological acceptance probability is equivalent to the calculation of the sample mean of a Bernoulli distribution. This allows the estimation of the acceptance probability to be preemptively terminated based on the current estimate and subject to the desired confidence level and interval length. We propose a composite uncertainty analysis of the hydrogeological heterogeneity utilizing acceptable realizations from multiple geostatistical models collected during the estimation of their acceptance probability. In the case of a non-fuzzy definition of realization acceptance, this produces a facies probability map. If the definition of realization acceptance is imprecise, the analysis yields upper and lower bounds on the facies probability map in the form of facies plausibility and belief maps, respectively. These maps can provide indications of the information content of the data and provide guidance for the collection of additional data.
Imaging the Disk and Jet of the Classical T Tauri Star AA Tau

Previous studies of the classical T Tauri star AA Tau have interpreted the UX-Orionis-like photo-polarimetric variability as being due to a warp in the inner disk caused by an inclined stellar magnetic dipole field. We test that these effects are macroscopically observable in the inclination and alignment of the disk. We use Hubble Space Telescope (HST)/STIS coronagraphic imagery to measure the V magnitude of the star for both STIS coronagraphic observations, compare these data with optical photometry in the literature, and find that, unlike other classical T Tauri stars observed in the same HST program, the disk is most robustly detected in scattered light at stellar optical minimum light.We measure the outer disk radius, 1 inch.15 plus-minus 0 inch.10, major-axis position angle, and disk inclination and find that the inner disk, as reported in the literature, is both misinclined and misaligned with respect to the outer disk. AA Tau drives a faint jet, detected in both STIS observations and in follow-on Goddard Fabry-Perot imagery, which is also misaligned with respect to the projection of the outer disk minor axis and is poorly collimated near the star, but which can be traced 21 inches from the star in data from 2005. The measured outer disk inclination, 71deg plus-minus 1deg, is out of the range of inclinations suggested for stars with UX-Orionis-like variability when no grain growth has occurred in the disk. The faintness of the disk, small disk size, and detection of the star despite the high inclination all indicate that the dust disk must have experienced grain growth and settling toward the disk midplane, which we verify by comparing the observed disk with model imagery from the literature.
PReBeaM for Planck: A Polarized Regularized Beam Deconvolution Map-Making Method

We describe a maximum-likelihood regularized beam deconvolution map-making algorithm for data from high-resolution, polarization-sensitive instruments, such as the Planck data set. The resulting algorithm, which we call PReBeaM, is pixel-free and solves for the map directly in spherical harmonic space, avoiding pixelization artifacts. While Fourier methods like ours are expected to work best when applied to smooth, large-scale asymmetric beam systematics (such as far-side lobe effects), we show that our m-truncated spherical harmonic representation of the beam results in negligible reconstruction error—even for m as small as 4 for a polarized elliptically asymmetric beam. We describe a hybrid OpenMP/MPI parallelization scheme which allows us to store and manipulate the time-ordered data from satellite instruments with a typical full-sky scanning strategy. Finally, we apply our technique to noisy data and show that it succeeds in removing visible power spectrum artifacts without generating excess noise on small scales.
Biomimetic hydroxylation of saturated carbons with artificial cytochrome P-450 enzymes-liberating chemistry from the tyranny of functional groups

Abstract Five mimics of cytochrome P-450 have been prepared and examined as catalysts for the specific hydroxylation of steroids. Reactions occur dictated by the geometries of the complexes, overcoming the intrinsic reactivity of a carbon–carbon double bond and of a secondary carbinol group. In some cases as many as 3000 catalytic turnovers are observed.
A Shape Annealing Approach to Optimal Truss Design With Dynamic Grouping of Members

A shape annealing approach to truss topology design is presented that considers the tradeoff between the mass of the structure and the grouping of members, where all members of a group are given the same size. The problem of optimal grouping involves finding a structural design with an optimal number of groups and the optimal sizes for each group. In this paper cross-sectional area is considered as the measure of group size. Designs incorporating multiple members with the same cross-sectional area are advantageous when considering the cost of purchasing and fabricating materials. The shape annealing method is used as an approach to solve this problem by incorporating a method for dynamic grouping of members based on cross-sectional area that creates a tradeoff between mass and the number of groups through a weighted objective function that includes a group penalty function. This method is demonstrated on transmission tower and general truss problems.
Inner Core Transition Zone and Anomalous PKP(DF) Waveforms from Polar Paths

[1] Short-period PKP(DF) waves (which travel through the inner core) from polar paths (nearly NS) were observed to have small amplitudes and complex waveforms but the cause has been a mystery. Here we examine both short-period and broadband PKP record sections from a single earthquake in South Sandwich Islands (SSI). The data from polar paths show clear evidence for an inner core triplication. Our waveform modeling suggests a 250-km thick isotropic upper inner core (UIC) overlying an anisotropic lower inner core (LIC) with about 8% anisotropy. The synthetics match the observed waveforms and amplitudes well with a normal value of inner core attenuation. We propose that such a UIC/LIC transition zone structure may be the cause of anomalous DF waveforms along polar paths. The inferred level of anisotropy in the LIC, 2–3 times previous estimates, has important implications for understanding physical properties of the inner core and sources of inner core anisotropy.
Giant Planets Orbiting Metal-rich Stars Show Signatures of Planet-Planet Interactions

Gas giants orbiting interior to the ice line are thought to have been displaced from their formation locations by processes that remain debated. Here we uncover several new metallicity trends, which together may indicate that two competing mechanisms deliver close-in giant planets: gentle disk migration, operating in environments with a range of metallicities, and violent planet-planet gravitational interactions, primarily triggered in metal-rich systems in which multiple giant planets can form. First, we show with 99.1% confidence that giant planets with semimajor axes between 0.1 and 1 AU orbiting metal-poor stars ([Fe/H] < 0) are confined to lower eccentricities than those orbiting metal-rich stars. Second, we show with 93.3% confidence that eccentric proto-hot Jupiters undergoing tidal circularization primarily orbit metal-rich stars. Finally, we show that only metal-rich stars host a pile-up of hot Jupiters, helping account for the lack of such a pile-up in the overall Kepler sample. Migration caused by stellar perturbers (e.g., stellar Kozai) is unlikely to account for the trends. These trends further motivate follow-up theoretical work addressing which hot Jupiter migration theories can also produce the observed population of eccentric giant planets between 0.1 and 1 AU.
Hyperbranched porphyrins—a rapid synthetic approach to multiporphyrin macromolecules

A new class of porphyrin containing hyperbranched polymers has been prepared via proton-transfer polymerisation utilising an A2 + B3 approach, thus providing an accelerated entry into the construction of branched multiporphyrin architectures.
The Atmospheric Infrared Sounder (AIRS) on the NASA Aqua Spacecraft: a general remote sensing tool for understanding atmospheric structure, dynamics, and composition

The Atmospheric Infrared Sounder (AIRS) on the EOS Aqua Spacecraft was launched on May 4, 2002. Early in the mission, the AIRS instrument demonstrated its value to the weather forecasting community with better than 6 hours of improvement on the 5 day forecast. Now with over eight years of consistent and stable data from AIRS, scientists are able to examine processes governing weather and climate and look at seasonal and interannual trends from the AIRS data with high statistical confidence. Naturally, long-term climate trends require a longer data set, but indications are that the Aqua spacecraft and the AIRS instrument should last beyond 2018. This paper briefly describes the AIRS data products and presents some of the most significant findings involving the use of AIRS data in the areas of weather forecast improvement, climate processes and model validation, cloud and polar processes, and atmospheric composition (chemistry and dust).
Somatosensory evoked potentials in the assessment of thoracic outlet compression syndrome

To evaluate the assessment of thoracic outlet compression syndrome (TOS) by objective methods, we prospectively studied a group of 80 consecutive patients with disabling TOS who had been selected for surgical therapy. Comprehensive pre- and postoperative neurophysiologic tests were used and included electromyography, nerve conduction times, F wave determination, and somatosensory evoked potentials (SEPs) of median and ulnar nerves in neutral and stressed positions. Measurements were made of Erb's point peak (N9), cervical peak (P/N13), and cortical complex (N18-P22). Amplitude ratios were calculated for each side, and interpeak latencies were measured for N9-P/N13, P/N13-N18, and N9-N18. SEP results were abnormal on the affected side in 59 of 80 patients (74%); ulnar peak amplitudes were either less than 33% of median, reduced by more than 50% in the stressed position, or reduced by more than 50% when compared with the contralateral side. Of 64 patients studied pre- and postoperatively with SEP, 40 of 47 abnormal tests showed improvement, with 30 of these returning to normal values in the early postoperative period. Excellent clinical correlation was evident in 43 of these 47 patients (92%) who had pre- and postoperative tests; with relief of symptoms reflected in improved SEP, or continued symptoms explained by evidence of persistent or residual nerve dysfunction. The present methodology and criteria for test interpretation demonstrate that SEP can document the neurocompressive component of TOS and provide an objective assessment of pre- and postoperative clinical observations.
Bilayer Protograph Codes for Half-Duplex Relay Channels

Despite encouraging advances in the design of relay codes, several important challenges remain. Many of the existing LDPC relay codes are tightly optimized for fixed channel conditions and not easily adapted without extensive re-optimization of the code. Some have high encoding complexity and some need long block lengths to approach capacity. This paper presents a high-performance protograph-based LDPC coding scheme for the half-duplex relay channel that addresses simultaneously several important issues: structured coding that permits easy design, low encoding complexity, embedded structure for convenient adaptation to various channel conditions, and performance close to capacity with a reasonable block length. The application of the coding structure to multi-relay networks is demonstrated. Finally, a simple new methodology for evaluating the end-to-end error performance of relay coding systems is developed and used to highlight the performance of the proposed codes.
Interaction versus dimerization in one-dimensional Fermi systems

In order to study the effect of interaction and lattice distortion on quantum coherence in one-dimensional Fermi systems, we calculate the ground state energy and the phase sensitivity of a ring of interacting spinless fermions on a dimerized lattice. Our numerical DMRG studies, in which we keep up to 1000 states for systems of about 100 sites, are supplemented by analytical considerations using bosonization techniques. We find a delocalized phase for an attractive interaction, which differs from that obtained for random lattice distortions. The extension of this delocalized phase depends strongly on the dimerization induced modification of the interaction. Taking into account the harmonic lattice energy, we find a dimerized ground state for a repulsive interaction only. The dimerization is suppressed at half filling, when the correlation gap becomes large.
Communications design for Co-oP: a group decision support system

Decision Support Systems (DSSs), computer-based systems intended to assist managers in preparing and analyzing decisions, have been single-user systems for most of the past decade. Only recently has DSS research begun to study the implications of the fact that most complex managerial decisions involve multiple decision makers and analysts. A number of tools for facilitating group decisions have been proposed under the label Group Decision Support Systems (GDSSs).One of the most important functions of a GDSS is to provide problem-oriented services for communication among decision makers. On the basis of an analysis of the communication requirements in various group decision settings, this paper presents an architecture for defining and enforcing dynamic application-level protocols that organize decision group interaction. The architecture has been implemented on a network of personal computers in Co-oP, a GDSS for cooperative group decision making based on interactive, multiple-criteria decision methods.
Distributed algorithmic mechanism design for scheduling on unrelated machines

In classical mechanism design the outcome of the mechanism is computed by a trusted central party. In this paper, we consider the design of distributed mechanisms in which the outcome is computed by the agents themselves. We propose Distributed MinWork (DMW), a mechanism for solving the problem of scheduling on unrelated machines. We show that DMW is a faithful implementation of the MinWork mechanism, which was proposed by Nisan and Ronen in their seminal work (Nisan and Ronen (2001) [30]). We show that in addition to being faithful, DMW protects the anonymity of the losing agents and the privacy of their bids. Furthermore, we show that DMW is efficient as it has polynomial communication and computation costs.
Large excimer lasers for fusion

Important goals in DOE and DoD programs require multimegajoule laser pulses. For inertial confinement fusion there is also a requirement to deliver the pulse in about 25 nsec with a very particular power vs time profile-all at high overall efficiency and low cost per joule. After exhaustive consideration of various alternatives, our studies have shown that the most cost effective approach to energy scaling is to increase the size of the final amplifiers up to the 200 to 300 Id level. This conclusion derives largely from the fact that, at a given complexity, costs increase slowly with increasing part size while output energy should increase dramatically. Extrapolations to low cost by drastic cuts in the unit cost of smaller devices through mass production are considered highly risky. At a minimum the requirement to provide, space, optics and mounts for such systems will remain expensive.
On the perpetual American put options for level dependent volatility models with jumps

We prove that the perpetual American put option price of level dependent volatility model with com- pound Poisson jumps is convex and is the classical solution of its associated quasi-variational inequality, that it is C 2 except at the stopping boundary and that it is C 1 everywhere (i.e. the smooth pasting condition always holds).
Asynchronous distributed detection

Binary parallel distributed-detection architectures employ a bank of local detectors to observe a common volume of surveillance, and form binary local decisions about the existence or nonexistence of a target in that volume. The local decisions are transmitted to a central detector, the data fusion center (DEC), which integrates them to a global target or no target decision. Most studies of distributed-detection systems assume that the local detectors are synchronized. In practice local decisions are made asynchronously and the DFC has to update its global decision continually. In this study the number of local decisions observed by the central detector within any observation period is Poisson distributed. An optimal fusion rule is developed and the sufficient statistic is shown to be a weighted sum of the local decisions collected by the DFC within the observation interval. The weights are functions of the individual local detector performance probabilities (i.e., probabilities of false alarm and detection). In this respect the decision rule is similar to the one developed by Chair and Varshney for the synchronized system. Unlike the Chair-Varshney rule, however, the DFC's decision threshold in the asynchronous system is time varying. Exact expressions and asymptotic approximations are developed for the detection performance with the optimal rule. These expressions allow performance prediction and assessment of tradeoffs in realistic decision fusion architectures which operate over modern communication networks. >
How credible are estimates of peasant allocative scale, or scope efficiency? A commentary

The bulk of the rapidly growing literature on the efficiency of peasant farmers around the world points to considerable economic inefficiencies, countering the Schultzian hypothesis of 'poor but efficient' producers in low-income agriculture. This commentary highlights several crucial weaknesses in contemporary methods of estimating economic efficiency parameters. While the efficiency of peasant producers is an issue of considerable policy importance, the methodological shortcomings of efficiency estimation render most exciting empirical findings uninformative. © 1997 by John Wiley & Sons, Ltd.
Octetonium at the LHC

Several models of new physics, such as grand unified theories, Pati-Salam models, chiral color models, etc., predict the existence of an S U ( 2 ) L doublet of color-octet scalars (COS). In the Manohar-Wise model, the Yukawa couplings of the COS are assumed to be consistent with Minimal Flavor Violation ensuring constraints from flavor physics are satisfied even for relatively light scalars. In this simple model we consider the production of color singlet bound states of COS that we call octetonium. Octetonium are mainly produced via gluon-gluon fusion and have significant production cross sections at the LHC. They can decay to pairs of gluons or electroweak gauge bosons. If the masses of the octetonia are 1 TeV or less, these states will be visible as resonances in γγ , W + W − , ZZ , and γZ .
Cycling of simple rules in the spatial model

McKelvey [4] proved that for strong simple preference aggregation rules applied to multidimensional sets of alternatives, the typical situation is that either the core is nonempty or the top-cycle set includes all available alternatives. But the requirement that the rule be strong excludes, inter alia, all supermajority rules. In this note, we show that McKelvey's theorem further implies that the typical situation for any simple rule is that either the core is nonempty or the weak top-cycle set (equivalently, the core of the transitive closure of the rule) includes all available alternatives. Moreover, it is often the case that both of these statements obtain.
Forced motion of a probe particle near the colloidal glass transition

We use confocal microscopy to study the motion of a magnetic bead in a dense colloidal suspension, near the colloidal glass transition volume fraction g. For dense liquid-like samples near g, below a threshold force the magnetic bead exhibits only localized caged motion. Above this force, the bead is pulled with a fluctuating velocity. The relationship between force and velocity becomes increasingly nonlinear as g is approached. The threshold force and nonlinear drag force vary strongly with the volume fraction, while the velocity fluctuations do not change near the transition.
Comparative catalytic C–H vs. C–Si activation of arenes with Pd complexes directed by urea or amide groups

Analysis of regiocontrol in Pd-catalysed C–H activation leads to observations of aryltrimethylsilyl activation and to superior results with urea-based substrates.
Selectfluor™-mediated allylstannation of aldehydes and imines

Abstract Reactions of aldehydes and imines with allyltributyltin catalyzed by Selectfluor™ in acetonitrile result in the formation of homoallylic alcohols and amines in good yields with excellent moisture and air tolerance.
Magnetic Properties of a Single Crystal of Manganese Phosphide

Magnetic measurements were made on a spherical single crystal of high-purity stoichiometric MnP with a vibrating-sample magnetometer which was modified to allow precise temperature control and temperature cycling from 4 to 500\ifmmode^\circ\else\textdegree\fi{}K. Anisotropy, saturation magnetization, and susceptibility data were obtained over this temperature range. The ferromagnetic Curie temperature was found to be 291.5\ifmmode\pm\else\textpm\fi{}0.2\ifmmode^\circ\else\textdegree\fi{}K. Evidence is presented which shows that MnP is neither ferrimagnetic nor antiferromagnetic, as has been previously supposed. Strong ferromagnetic coupling between spins may be assumed from the fact that the $\frac{1}{\ensuremath{\chi}}$ versus $T$ curve has strong concave-up curvature above the Curie point. A magnetic transformation, not previously reported, was observed at 50\ifmmode^\circ\else\textdegree\fi{}K which may be interpreted in terms of temperature-dependent, competing antiferromagnetic-ferromagnetic interactions. Below 50\ifmmode^\circ\else\textdegree\fi{}K, MnP is metamagnetic, i.e., it exhibits an antiferromagnetic-ferromagnetic transition which is a function of applied field and temperature.
Eternal Quest for the Best: Sequential (vs. Simultaneous) Option Presentation Undermines Choice Commitment

A series of laboratory and field experiments reveals a detrimental effect of presenting options sequentially (one at a time) versus simultaneously (all at once) on choosers’ satisfaction with and commitment to their chosen option. This is because choosers presented with their options simultaneously tend to remain focused on the current set of options, comparing them among each other; whereas choosers presented with their options sequentially tend to imagine a better option, hoping it will become available. This feeling of hope undermines how choosers subsequently experience their selected option, resulting in lower satisfaction and commitment levels. Sequential choosers consequently exhibit lower outcome satisfaction regardless of which option they choose, whether sequentially passed-up options remain available, and whether they have equivalent option information to simultaneous choosers. Thus, enjoying the most satisfaction from one’s choice might require being willing to give up the eternal quest for th...