cssi/SciSciGPT-SciSciNet huggingface dataset:
Observations of neutron-capture elements in the early galaxy

Abstract Neutron-capture elements in low metallicity Galactic halo stars vary widely both in overall contents and detailed abundance patterns. This review discusses recent observational results of the n-capture elements, discussing the implications for early Galactic nucleosynthesis of: (a) the star-to-star “bulk” variations in the n-capture/Fe abundance ratios; (b) the distinct signature of rapid n-capture synthesis events in many (most?) of the lowest metallicity stars; (c) the existence of metal-poor stars heavily enriched in the products of slow n-capture synthesis reactions; and (d) the now-routine detection of radioactive thorium (and even uranium in one and possibly two cases) in the spectra of metal-poor stars.
TOWARDS THE THEORY OF STATIONARY UNIVERSE.

This talk presents some progress achieved in collaboration with A.Linde and D.Linde towards understanding the true nature of the global spatial structure of the Universe as well as the most general stationary characteristics of its time-dependent state with eternally growing total volume.
Apparent transgenerational effects of host plant in the leaf beetle Ophraella notulata (Coleoptera: Chrysomelidae)

The natural host of Ophraella notulata is Iva frutescens (Asteraceae); its close relative feeds on a related plant, Ambrosia artemisiifolia. We reared beetles on both plants, obtained progeny from the four possible crosses (two sexes X two parental hosts), and reared the progeny on both plant species. Survival to the imaginal stage of progeny reared on Iva varied with both maternal and paternal host. Hatchling feeding response to both plants showed a maternal host X paternal host interaction. Consumption of Ambrosia by adult beetles was, counter to expectation, higher for progeny of Iva-reared males than Ambrosia-reared males. Oviposition response, although based on too few data to be definitive, was peculiar: parental host did not affect oviposition on Ambrosia; on Iva daughters of Iva-reared males laid significantly more eggs than did daughters of Ambrosia-reared males, but only if they had been reared on Iva; those reared on Ambrosia displayed the reverse pattern. We discuss the possibility that nongenetic paternal transmission of host plant effects may explain these results, but offer a somewhat uncomfortable hypothesis of selection as a preferable explanation. An important outcome of the experiment is that it provided no evidence of maternal effects of host plant on offspring feeding or oviposition.
Self-Intersection Numbers of Curves in the Doubly Punctured Plane

We address the problem of computing bounds for the self-intersection number (the minimum number of generic self-intersection points) of members of a free homotopy class of curves in the doubly punctured plane as a function of their combinatorial length L; this is the number of letters required for a minimal description of the class in terms of a set of standard generators of the fundamental group and their inverses. We prove that the self-intersection number is bounded above by L 2/4+L/2−1, and that when L is even, this bound is sharp; in that case, there are exactly four distinct classes attaining that bound. For odd L we conjecture a smaller upper bound, (L 2−1)/4, and establish it in certain cases in which we show that it is sharp. Furthermore, for the doubly punctured plane, these self-intersection numbers are bounded below, by L/2−1 if L is even, and by (L−1)/2 if L is odd. These bounds are sharp.
Interpolating the nucleon's spin-dependent sum rules at high and low energies

Abstract I discuss a few interpolating sum rules for spin functions of the nucleon. Using the concept of duality, I argue that the G 1 sum rule, including the elastic contribution, is useful for learning higher twist matrix elements of the nucleon.
Estimate of Enthalpies of Formation and Fusion of Cordierite

The enthalpies of solution in molten 2PbO·B2O3 at 690°±2°C of cordierite, Mg2Al4Si5O18, and of a glass of cordierite composition were determined. From these data, the enthalpy of formation of cordierite from the component oxides is -16.1±1.7 kcal/mol and its heat of fusion +54.0±2.0 kcal/mol.
Compressed Cesium Polyhydrides: Cs+ Sublattices and H3– Three-Connected Nets

The cesium polyhydrides (CsHn, n > 1) are predicted to become stable, with respect to decomposition into CsH and H2, at pressures as low as 2 GPa. The CsH3 stoichiometry is found to have the lowest enthalpy of formation from CsH and H2 between 30 and 200 GPa. Evolutionary algorithms predict five distinct, mechanically stable, nearly isoenthalpic CsH3 phases consisting of H3– molecules and Cs+ atoms. The H3– sublattices in two of these adopt a hexagonal three-connected net; in the other three the net is twisted, like the silicon sublattice in the α-ThSi2 structure. The former emerge as being metallic below 100 GPa in our screened hybrid density functional theory calculations, whereas the latter remain insulating up to pressures greater than 250 GPa. The Cs+ cations in the most-stable I41/amd CsH3 phase adopt the positions of the Cs atoms in Cs-IV, and the H3– molecules are found in the (interstitial) regions which display a maximum in the electron density.
Industrial perspectives panel

This year, we have a different format for HPCA's industrial session. We will have an “industrial perspectives panel” with practitioners from industry presenting their perspectives on interesting future technical challenges and opportunities for research. We have panelists from IBM, Microsoft, NVIDIA, and Sun exploring a spectrum of interesting areas from consumer to enterprise markets including “hot” topics around multicores, graphics accelerators, and solid-state memory.
Phase Mixing in Unperturbed and Perturbed Hamiltonian Systems

This paper summarises a numerical investigation of phase mixing in time-independent Hamiltonian systems that admit a coexistence of regular and chaotic phase space regions, allowing also for low amplitude perturbations idealised as periodic driving, friction, and/or white and coloured noise. The evolution of initially localised ensembles of orbits was probed through lower order moments and coarse-grained distribution functions. In the absence of time-dependent perturbations, regular ensembles disperse initially as a power law in time and only exhibit a coarse-grained approach towards an invariant equilibrium over comparatively long times. Chaotic ensembles generally diverge exponentially fast on a time scale related to a typical finite time Lyapunov exponent, but can exhibit complex behaviour if they are impacted by the effects of cantori or the Arnold web. Viewed over somewhat longer times, chaotic ensembles typical converge exponentially towards an invariant or near-invariant equilibrium. This, however, need not correspond to a true equilibrium, which may only be approached over very long time scales. Time-dependent perturbations can dramatically increase the efficiency of phase mixing, both by accelerating the approach towards a near-equilibrium and by facilitating diffusion through cantori or along the Arnold web so as to accelerate the approach towards a true equilibrium. The efficacy of such perturbations typically scales logarithmically in amplitude, but is comparatively insensitive to most other details, a conclusion which reinforces the interpretation that the perturbations act via a resonant coupling.
Local Lagrangian formalism and discretization of the Heisenberg magnet model

In this paper we develop the Lagrangian and multisymplectic structures of the Heisenberg magnet (HM) model which are then used as the basis for geometric discretizations of HM. Despite a topological obstruction to the existence of a global Lagrangian density, a local variational formulation allows one to derive local conservation laws using a version of Nother's theorem from the formal variational calculus of Gelfand-Dikii. Using the local Lagrangian form we extend the method of Marsden, Patrick and Schkoller to derive local multisymplectic discretizations directly from the variational principle. We employ a version of the finite element method to discretize the space of sections of the trivial magnetic spin bundle N=MxS^2 over an appropriate space-time M. Since sections do not form a vector space, the usual FEM bases can be used only locally with coordinate transformations intervening on element boundaries, and conservation properties are guaranteed only within an element. We discuss possible ways of circumventing this problem, including the use of a local version of the method of characteristics, non-polynomial FEM bases and Lie-group discretization methods.
DataSpaces: an interaction and coordination framework for coupled simulation workflows

Emerging high-performance distributed computing environments are enabling new end-to-end formulations in science and engineering that involve multiple interacting processes and data-intensive application workflows. For example, current fusion simulation efforts are exploring coupled models and codes that simultaneously simulate separate application processes, such as the core and the edge turbulence. These components run on different high performance computing resources, need to interact at runtime with each other and with services for data monitoring, data analysis and visualization, and data archiving. As a result, they require efficient and scalable support for dynamic and flexible couplings and interactions, which remains a challenge. This paper presents DataSpaces a flexible interaction and coordination substrate that addresses this challenge. DataSpaces essentially implements a semantically specialized virtual shared space abstraction that can be associatively accessed by all components and services in the application workflow. It enables live data to be extracted from running simulation components, indexes this data online, and then allows it to be monitored, queried and accessed by other components and services via the space using semantically meaningful operators. The underlying data transport is asynchronous, low-overhead and largely memory-to-memory. The design, implementation, and experimental evaluation of DataSpaces using a coupled fusion simulation workflow is presented.
One-dimensional string theory on a circle

We discuss random matrix-model representations of D = 1 string theory, with particular emphasis on the case in which the target space is a circle of finite radius. The duality properties of discretized strings are analyzed and shown to depend on the dynamics of vortices. In the representation in terms of a continuous circle of matrices we find an exact expression for the free energy, neglecting non-singlet states, as a function of the string coupling and the radius which exhibits exact duality. In a second version, based on a discrete chain of matrices, we find that vortices induce, for a finite radius, a Kosterlitz-Thouless phase transition that takes us to a c = 0 theory.
A STUDY OF ALFVÉN WAVE PROPAGATION AND HEATING THE CHROMOSPHERE

Alfven wave propagation, reflection, and heating of the chromosphere are studied for a one-dimensional solar atmosphere by self-consistently solving plasma, neutral fluid, and Maxwell's equations with incorporation of the Hall effect and strong electron-neutral, electron-ion, and ion-neutral collisions. We have developed a numerical model based on an implicit backward difference formula of second-order accuracy both in time and space to solve stiff governing equations resulting from strong inter-species collisions. A non-reflecting boundary condition is applied to the top boundary so that the wave reflection within the simulation domain can be unambiguously determined. It is shown that due to the density gradient the Alfven waves are partially reflected throughout the chromosphere and more strongly at higher altitudes with the strongest reflection at the transition region. The waves are damped in the lower chromosphere dominantly through Joule dissipation, producing heating strong enough to balance the radiative loss for the quiet chromosphere without invoking anomalous processes or turbulences. The heating rates are larger for weaker background magnetic fields below ~500 km with higher-frequency waves subject to heavier damping. There is an upper cutoff frequency, depending on the background magnetic field, above which the waves are completely damped. At the frequencies below which the waves are not strongly damped, the interaction of reflected waves with the upward propagating waves produces power at their double frequencies, which leads to more damping. The wave energy flux transmitted to the corona is one order of magnitude smaller than that of the driving source.
Profiling the reference price consumer

Researchers in marketing have devoted considerable attention to understanding how price impacts the purchase decision. Some individuals, termed memory-based reference price (MBR) consumers, take into account price expectations developed from past purchase behavior when making a current choice. Other individuals, termed stimulus-based reference price (SBR) consumers, make choices by constructing a reference point from the currently observed distribution of prices. Using a latent class model of structural heterogeneity applied to purchase histories from the toilet tissue category, we classify households in terms of the pricing mechanism used in buying decisions. We find strong evidence that memory-based (internal) reference price consumers are more price sensitive than other consumers. Moreover, we find that variables associated with the accessibility of price information are predictive of consumer use of memory-based reference prices. Managerial implications of these results are discussed.
An unbiased model comparison test using cross-validation

Social scientists often consider multiple empirical models of the same process. When these models are parametric and non-nested, the null hypothesis that two models fit the data equally well is commonly tested using methods introduced by Vuong (Econometrica 57(2):307–333, 1989) and Clarke (Am J Political Sci 45(3):724–744, 2001; J Confl Resolut 47(1):72–93, 2003; Political Anal 15(3):347–363, 2007). The objective of each is to compare the Kullback–Leibler Divergence (KLD) of the two models from the true model that generated the data. Here we show that both of these tests are based upon a biased estimator of the KLD, the individual log-likelihood contributions, and that the Clarke test is not proven to be consistent for the difference in KLDs. As a solution, we derive a test based upon cross-validated log-likelihood contributions, which represent an unbiased KLD estimate. We demonstrate the CVDM test’s superior performance via simulation, then apply it to two empirical examples from political science. We find that the test’s selection can diverge from those of the Vuong and Clarke tests and that this can ultimately lead to differences in substantive conclusions.
Noble gases in planetary atmospheres: Implications for the origin and evolution of atmospheres☆

The radiogenic and primordial noble gas contents of the Venus, earth, and Mars atmospheres are compared with one another and with the noble gas content of other extraterrestrial samples, particularly meteorites. Key trends in the primordial noble gas content of terrestrial planetary atmospheres are shown to include: (1) a several-orders-of-magnitude decrease in Ne-20 and Ar-36 from Venus to earth to Mars; (2) a nearly constant Ne-20/Ar-36 ratio, which is comparable to that found in the more primitive carbonaceous chondrites and which is two orders of magnitude smaller than the solar ratio; (3) a sizable fractionation of Ar, Kr, and Xe from their solar ratios, though the degree of fractionation (especially for Ar-36/Xe-132) appears to decrease systematically from carbonaceous chondrites to Mars to earth to Venus; and (4) large differences in Ne and Xe isotopic ratios among earth, meteorites, and the sun. It is suggested that the grain-accretion hypothesis can explain all four trends, though the assumptions needed to achieve this agreement are far from proven.
Slot-mode-coupled optomechanical crystals.

We present a design methodology and analysis of a cavity optomechanical system in which a localized GHz frequency mechanical mode of a nanobeam resonator is evanescently coupled to a high quality factor (Q>10^6) optical mode of a separate nanobeam optical cavity. Using separate nanobeams provides flexibility, enabling the independent design and optimization of the optics and mechanics of the system. In addition, the small gap (≈25 nm) between the two resonators gives rise to a slot mode effect that enables a large zero-point optomechanical coupling strength to be achieved, with g/2π > 300 kHz in a Si_3N_4 system at 980 nm and g/2π ≈900 kHz in a Si system at 1550 nm. The fact that large coupling strengths to GHz mechanical oscillators can be achieved in SiN is important, as this material has a broad optical transparency window, which allows operation throughout the visible and near-infrared. As an application of this platform, we consider wide-band optical frequency conversion between 1300 nm and 980 nm, using two optical nanobeam cavities coupled on either side to the breathing mode of a mechanical nanobeam resonator.
A NON-STANDARD STRING EMBEDDING OF E8

An algorithm to systematically and efficiently generate free fermionic heterotic string models was recently introduced.1 This algorithm has been adopted by the Free Fermionic Model Construction (FFMC) program at Baylor University. As its first application, the algorithm is being applied to systematically generate the complete set of free fermionic heterotic string models with untwisted left-moving (worldsheet supersymmetric) sectors, up to continually advancing Layer and Order. Statistical analysis of this study will be reported in the near future. However, in a series of separate notes we will be reporting some of the more interesting models that appear along the way. In this, our first such note, we reveal a different string embedding of E8 than is standard. That is, rather than realize E8 via an SO(16) embedding, 248 = 120 + 128, we realize it via an SU(9) embedding, . This is obtained in a Layer 1, Order 6 model for which modular invariance itself dictates a gravitino sector accompany the gauge sector.
A common language for hardware, software, and applications

Algorithms commonly used in automatic data processing are, when considered in terms of the sequence of individual physical operations actually executed, incredibly complex. Such algorithms are normally made amenable to human comprehension and analysis by expressing them in a more compact and abstract form which suppresses systematic detail. This suppression of detail commonly occurs in several fairly well defined stages, providing a hierarchy of distinct descriptions of the algorithm at different levels of detail. For example, an algorithm expressed in the FORTRAN language may be transformed by a compiler to a machine code description at a greater level of detail which is in turn transformed by the "hardware" of the computer into the detailed algorithm actually executed.
Comment on “The Cosmic Time in Terms of the Redshift,” by Carmeli et al.

The time-redshift relation of Carmeli et al. differs from that of the standard flat ΛCDM model by more than 500 million years for 1 ≤ z ≤ 4.5.
Do Proto-jovian Planets Drive Outflows?

We discuss the possibility that gaseous giant planets drive strong outflows during early phases of their formation. We consider the range of parameters appropriate for magneto-centrifugally driven stellar and disk outflow models and find that, if the proto-Jovian planet or accretion disk had a magnetic field of 10 G and moderate mass-inflow accretion rates through the disk of less than ~10-7MJ yr-1, it is possible to drive an outflow. Estimates based both on scaling from empirical laws observed in protostellar outflows and the magneto-centrifugal disk and stellar plus disk wind models suggest that winds with mass-outflow rates of order 10-8MJ yr-1 and velocities of order ~20 km s-1 could be driven from proto-Jovian planets. Prospects for detection and some implications for the formation of the solar system are briefly discussed.
Development of a Coupled Approach for Structural Damage Detection with Incomplete Measurements

A procedure has been developed that couples model order reduction, damage location, dynamic residual and mode shape expansion, and damage extent estimation to overcome the incomplete measurements problem by using an appropriate undamaged structural model. The first significant contribution of this work is in the development of a process to estimate the full dynamic residuals using the columns of a spring connectivity matrix obtained by disassembling the structural stiffness matrix. The second significant contribution is the extension of an eigenvector filtering procedure to produce full-order mode shapes that more closely match the measured active partition of the mode shapes using a series of modified Ritz vectors. The full dynamic residuals and full mode shapes are used as inputs to the minimum rank perturbation theory to provide an estimate of damage location and extent. An analytical model of the NASA eight-hay truss and an experimental data set are used to exercise this process and to study the sensitivity to various parameters.
New Ideas and Developments in Calorimetry

The challenges for calorimeter performance in the next decade are reviewed. Some new ideas for calorimeters are described: (1) the test of a parallel plate calorimeter; (2) the use of vacuum photodiodes for calorimeters operating in a magnetic field; (3) the attempt to build high pressure gas sealed tubes as ion chambers in hadron calorimeters; (4) the progress in the attempt to mold plastic loaded with heavy metal for the inert material in gas calorimeters; (5) the use of the limited streamer mode in calorimeters.
Adenovirus infection induces microglial activation: involvement of mitogen‐activated protein kinase pathways

Non-replicating adenovirus (Ad) vectors represent effective tools for long-term gene expression in the CNS, but they also elicit inflammation. The cellular and molecular mechanisms of such a response are not well-understood. We show here that infection with Ad causes an activation of microglial cells, the key cells involved in inflammatory and immune-regulatory functions in the brain. Exposure of cultured rat brain microglia to Ad resulted in an induced production of nitric oxide (NO) and the expression of inducible nitric oxide synthase (iNOS) and the pro-inflammatory cytokine, TNFα. The roles of signal transduction pathways believed to be involved in microglial activation, in particular, mitogen-activated protein kinases (MAPKs) and nuclear factor κB (NFκB) were explored by determining their activation in response to Ad infection and by testing the effects of specific pharmacological inhibitors. It was found that Ad strongly activates extracellular signal-regulated kinase (ERK) and to a lesser extent, p38 MAPK but not NFκB. The kinase inhibitor i.e. PD98059, specific for the ERK pathway, potently inhibits and, in combination with the p38 MAPK inhibitor, SB203580, almost completely abolishes Ad-induced expression of iNOS and TNFα. The results suggest that Ad uses cellular signal transduction machinery, in particular, the ERK pathway to elicit microglial activation and that increased production by these cells of inflammatory mediators may primarily contribute to CNS inflammatory responses commonly seen in models of gene therapy using Ad vectors. Acknowledgements: Supported by NINDS grant # NS41035-01.
IDENTIFYING REGIME CHANGES IN MARKET VOLATILITY

A casual inspection of a graph of volatility indexes over time indicates that volatility has undergone infrequent, but significant, shifts in its average level. The purpose of this article is to test for multiple structural breaks in the mean level of market volatility measured by the VIX and VXO, and to identify statistically the dates of these mean shifts. We find evidence of three distinct periods: pre-1992, 1992–1997, and post-1997. We find that the mean volatility, as well as its standard deviation, was lowest during 1992–1997. Our findings provide statistical evidence consistent with popular beliefs that market volatility changes over time.
Voyager observations of low-energy ions during solar cycle 23

Abstract We report on observations at Voyagers 1 and 2, in the outer heliosphere, of ions with energies ∼30 keV to 30 MeV. The period of interest is from 2001 through 2002 DOY 268, during which both spacecraft observe significant variations in energetic ion intensities as large-scale plasma disturbances associated with intense periods of solar activity in 2000–2002 reach the outer heliosphere.
Catalytic carbopalladation of ω-methylenebicyclo[n.1.0]alkanes

Abstract ω-Methylenebicyclo[n.1.0]alkanes undergo carbopalladation via cleavage of the C(1)C(2) cyclopropane bond. The resultant σ-butenyl complexes decompose via β-hydride elimination to afford the 1-cycloalkenylstyrene products.
Response to comment on “The National Ignition Facility laser performance status”

We appreciate Stephen Bodner's continuing interest in the performance of the NIF laser system. However, we find it necessary to disagree with the conclusions he reached in his comments [Appl. Opt.47, XXX (2008)] on “National Ignition Facility Laser Performance Status” [Appl. Opt.46, 3276 (2007)]. In fact, repeated and ongoing tests of the NIF beamlines have demonstrated that NIF can be expected not only to meet or exceed its requirements as established in the mid-1990s in the document National Ignition Facility Functional Requirements and Primary Criteria [Revision 1.3, Report NIF-LLNL-93-058 (1994)], but also to have the flexibility that provides for successfully meeting an ever expanding range of mission goals, including those of ignition.
Not yet dead at the fed: Unions, worker bargaining, and economy-wide wage determination

Transcripts of the Federal Open Market Committee (FOMC) of the Federal Reserve and related documents provide new insights into how macro-policy makers characterized the labor market. Over the period of the 1980s and the 1990s, the Federal Reserve seemingly overemphasized the significance of union settlements, characterizing them in wage-push terms out of proportion to declining union density. Fed policy makers expressed surprise that the nonaccelerating inflation rate of unemployment (NAIRU) dropped during this period and offered various ad hoc explanations to explain the drop. The underlying common element of these explanations is that they were based on a rhetorical bargaining framework, explicit or implicit, that workers bargain as active agents for wages. Along with ongoing direct discussion of union settlements, this tendency suggests a view of worker bargaining power that seems at variance with union decline and the reality of an increasingly nonunion labor market. While worker bargaining models can be reconciled in a formal sense with various theories of nonunion wage determination, the ability of such models to realistically explain the macro outcomes that puzzled and challenged policy makers can be questioned.
On-board hydrogen storage and production: An application of ammonia electrolysis

Abstract On-board hydrogen storage and production via ammonia electrolysis was evaluated to determine whether the process was feasible using galvanostatic studies between an ammonia electrolytic cell (AEC) and a breathable proton exchange membrane fuel cell (PEMFC). Hydrogen-dense liquid ammonia stored at ambient temperature and pressure is an excellent source for hydrogen storage. This hydrogen is released from ammonia through electrolysis, which theoretically consumes 95% less energy than water electrolysis; 1.55 Wh g −1 H 2 is required for ammonia electrolysis and 33 Wh g −1 H 2 for water electrolysis. An ammonia electrolytic cell (AEC), comprised of carbon fiber paper (CFP) electrodes supported by Ti foil and deposited with Pt–Ir, was designed and constructed for electrolyzing an alkaline ammonia solution. Hydrogen from the cathode compartment of the AEC was fed to a polymer exchange membrane fuel cell (PEMFC). In terms of electric energy, input to the AEC was less than the output from the PEMFC yielding net electrical energies as high as 9.7 ± 1.1 Wh g −1 H 2 while maintaining H 2 production equivalent to consumption.
A short synthesis of (±)-tecomanine via a Pauson–Khand-based route

The N-carboethoxy precursor to (±)-tecomanine has been prepared in 11 steps from 2-methyl-1-buten-3-yne. The key step, Pauson–Khand cyclization of a methylated 5-aza-6-nonen-1-yne succeeds, but only in low yield, a consequence of the dialkyl substitution about the azaenyne framework. Nevertheless, the overall sequence to that point is one of the more efficient to be described.
Light Curves and Spectra of Dust Echoes from Gamma-Ray Bursts and Their Afterglows: Continued Evidence That GRB 970228 Is Associated with a Supernova

The relative brightening and reddening of the optical afterglows of GRB 970228 and GRB 980326 around 20-30 days after these bursts have been attributed to supernovae, which are red (blueward of their spectral peak) and which peak in time after ≈20(1 + z) days. However, this direct evidence for a gamma-ray burst/supernova (GRB/SN) connection has recently been challenged. It has been suggested that the late afterglows of these bursts can be explained by dust echoes, of which we consider two cases: (1) the scattering of light from the afterglow (the forward shock), the optical flash (the reverse shock), and/or the optical light from the burst itself by a shell of dust at a radius R from the progenitor and (2) the absorption and thermal reemission of this light by this shell of dust. In this paper, we model and compute dust echo light curves and spectra for both cases. Although the late-time afterglow of GRB 980326 was not sufficiently well sampled to rule out a dust echo description, we find that the late-time afterglow of GRB 970228 cannot be explained by a dust echo.
Effect of hand-based sensors on manipulator control performance

Manipulator task categories and motion phases require various hand-based information systems to meet the control performance requirements. The effect of proximity, tactile and force/torque sensors on the performance of remote manipulator control is discussed. An overview is presented on various experimental hand-based information systems which provide the manipulator controller some non-visual 'awareness' of the task environment. The rest of the paper describes and evaluates various control experiments performed at JPL using hand-mounted proximity sensors to guide and control hand motion near solid objects.
Generation and transfer of single photons on a photonic crystal chip

We present a basic building block of a quantum network consisting of a quantum dot coupled to a source cavity, which in turn is coupled to a target cavity via a waveguide. The single photon emission from the high-Q/V source cavity is characterized by twelve-fold spontaneous emission (SE) rate enhancement, SE coupling efficiency β ∼ 0.98 into the source cavity mode, and mean wavepacket indistinguishability of ∼67%. Single photons are efficiently transferred into the target cavity via the waveguide, with a target/source field intensity ratio of 0.12 ± 0.01. This system shows great promise as a building block of future on-chip quantum information processing systems.
Preoperative lymph node staging of early-stage cervical carcinoma by [18F]-fluoro-2-deoxy-D-glucose-positron emission tomography

BACKGROUND Increasing evidence has documented the value of positron emission tomography (PET) in oncology, but only limited data are available comparing PET findings with the pathologic status of regional lymph nodes in patients with cervical carcinoma. The objective of this study was to determine the sensitivity and specificity of PET in detecting lymph node metastasis in women with early-stage cervical carcinoma. METHODS The authors performed a retrospective review of all patients with Stage IA–IIA cervical carcinoma who underwent PET before surgery from 1999 to 2004. The status of the regional lymph nodes was correlated with lymph node pathology. RESULTS Fifty-nine patients were identified. Pelvic lymph node metastases were present in 32% of the patients and were detected by PET with a sensitivity of 53%, a specificity of 90%, a positive predictive value (PPV) of 71%, and a negative predictive value (NPV) of 80%. Paraaortic lymph node disease was present in 9% of patients and was detected by PET with a sensitivity of 25%, a specificity 98%, a PPV of 50%, and an NPV of 93%. The mean size of the tumor deposits was larger in the PET-positive pelvic nodes (15.2 mm; range, 2–35 mm) than in the PET-negative lymph nodes (7.3 mm; range, 0.3–20 mm; P = 0.002). Computed tomography (CT) scans were obtained before surgery in 42 patients. The combined sensitivity of PET and CT in these patients was 75%. PET alone detected 9 (36%) of the positive lymph node groups, whereas CT alone detected 3 (12%) of the positive lymph node groups. Neither PET nor CT detected the positive lymph node groups in 8 patients (32%). CONCLUSIONS Pathologic validation of PET imaging demonstrated a low sensitivity and a high specificity for PET in patients with early-stage cervical carcinoma. Cancer 2005. © 2005 American Cancer Society.
Effects of rim thickness on spur gear bending stress

Thin rim gears find application in high-power, light-weight aircraft transmissions. Bending stresses in thin rim spur gear tooth fillets and root areas differ from the stresses in solid gears due to rim deformations. Rim thickness is a significant design parameter for these gears. To study this parameter, a finite element analysis was conducted on a segment of a thin rim gear. The rim thickness was varied and the location and magnitude of the maximum bending stresses reported. Design limits are discussed and compared with the results of other researchers.
Factors that may influence or hinder use of instructional technology among accounting faculty

Purpose – To determine what factors influence faculty's decisions to use technology in their classes, what factors prevent them from use, and whether there are differences among faculty by gender, ethnicity, rank, sub‐areas, etc. in using instructional technology.Design/methodology/approach – A survey instrument was used to measure attitudes toward technology among accounting educators. The instrument included three separate sections. The first section was devoted to examining factors that could influence faculty's opinion to use technology for teaching. The second section focused on issues that could possibly discourage faculty from use of technology. For these two sections a five‐point Likert scale was developed with possible responses ranging from “not important” to “critically important”. The third and final section was designed to provide demographic information for classification purposes and testing of the research questions.Findings – The results demonstrate that while accounting faculty value tec...
Have the poor always been less likely to migrate? Evidence from inheritance practices during the age of mass migration

Using novel data on 50,000 Norwegian men, we study the effect of wealth on the probability of internal or international migration during the Age of Mass Migration (1850–1913), a time when the US maintained an open border to European immigrants. We do so by exploiting variation in parental wealth and in expected inheritance by birth order, gender composition of siblings, and region. We find that wealth discouraged migration in this era, suggesting that the poor could be more likely to move if migration restrictions were lifted today. We discuss the implications of these historical findings to developing countries.
Sling plication for recurrent stress urinary incontinence.

OBJECTIVES : Management of recurrent stress urinary incontinence (SUI) after synthetic mid-urethral sling placement is a challenging clinical dilemma. This case series describes a safe, minimally invasive treatment option for recurrent SUI after failure of the primary mid-urethral sling procedure. METHODS : Twenty women with recurrent SUI after previous synthetic mid-urethral sling placement underwent plication of the sling with 2-0 polyester suture under intravenous sedation with an intra-operative cough stress test between December 2004 and December 2008. A retrospective chart review was performed to obtain pertinent preoperative and postoperative data. RESULTS : Nine of the patients had prior retropubic synthetic mid-urethral slings. The other 11 women had transobturator mid-urethral slings, 10 of whom had slings via the outside-in approach and 1 had a single-incision mini-sling placed. The mean patient age was 59.8 years (range 38-83 years). Sling plication was performed at a median of 159.5 days after initial sling placement (range 26-2090 days). Overall 85% of patients had subjective improvement in SUI after sling plication with a median follow-up of 54.5 days (range 29-972 days). Those patients with prior retropubic slings had a 100% improvement rate compared to 72% improvement with prior obturator slings (P = 0.22). The subjective cure rate was 65%, 88% for the retropubic slings and 45% for the transobturator slings (P = 0.07). There were no complications. CONCLUSIONS : Midline plication of previously placed synthetic mid-urethral slings is a safe and effective method of treating recurrent SUI.
THE PARSEC-SCALE ACCRETION DISK IN NGC 3393

We present a Very Long Baseline Interferometry image of the water maser emission in the nuclear region of NGC 3393. The maser emission has a linear distribution oriented at a position angle of ~–34°, perpendicular to both the kiloparsec-scale radio jet and the axis of the narrow-line region. The position-velocity diagram displays a red-blue asymmetry about the systemic velocity and the estimated dynamical center, and is thus consistent with rotation. Assuming Keplerian rotation in an edge-on disk, we obtain an enclosed mass of -->(3.1 ± 0.2) × 107 M☉ within -->0.36 ± 0.02 pc ( -->1.48 ± 0.06 mas), which corresponds to a mean mass density of ~108.2 M☉ pc−3. We also report the measurement with the Green Bank Telescope of a velocity drift, a manifestation of centripetal acceleration within the disk, of -->5 ± 1 km s−1 yr−1 in the ~3880 km s−1 maser feature, which is most likely located along the line of sight to the dynamical center of the system. From the acceleration of this feature, we estimate a disk radius of -->0.17 ± 0.02 pc, which is smaller than the inner disk radius ( -->0.36 ± 0.02 pc) of emission that occurs along the midline (i.e., the line of nodes). The emission along the line of sight to the dynamical center evidently occurs much closer to the center than the emission from the disk midline, contrary to the situation in the archetypal maser systems NGC 4258 and NGC 1068. The outer radius of the disk as traced by the masers along the midline is about 1.5 pc.
Redox Mediators in Visible Light Photocatalysis: Photocatalytic Radical Thiol–Ene Additions

Synthetically useful radical thiol–ene reactions can be initiated by visible light irradiation in the presence of transition metal polypyridyl photocatalysts. The success of this method relies upon the use of p-toluidine as an essential additive. Using these conditions, high-yielding thiol–ene reactions of cysteine-containing biomolecules can be accomplished using biocompatibile wavelengths of visible light, under aqueous conditions, and with the thiol component as the limiting reagent. We present evidence that p-toluidine serves as a redox mediator that is capable of catalyzing the otherwise inefficient photooxidation of thiols to the key thiyl radical intermediate. Thus, we show that co-catalytic oxidants can be important in the design of synthetic reactions involving visible light photoredox catalysis.
The Impact of Wives’ Earnings on Earnings Inequality Among Married-Couple Households in Malaysia

Abstract Using data from the First and Second Malaysian Family Life Surveys, we analyze the effects of wives’ earnings on household earnings’ inequality in Peninsular Malaysia in 1976 and 1988. We find that wives’ earnings helped equalize the distribution of household earnings in Malaysia, both at the two points in time and over time. The equalizing effect of wives’ earnings over time is in part due to the fact that the correlation between husbands’ and wives’ earnings decreased between 1976 and 1988.
Propene alkylation of liquid phase biphenyl catalyzed by alumina pillared clay catalysts

Abstract The propene alkylation of liquid phase biphenyl has been catalyzed by several alumina pillared clays. The study included clays of various charge densities, charge localization and extent of layer stacking. For comparison purposes, the performance of an add washed montmorillonite (K10) and two zeolites (H-mordenite and USY) were also investigated. Under liquid phase reaction conditions at 250°C and 140 psi propene, the reaction over pillared days was under diffusion control. Thus, the activities and selectivities of the catalysts were very dependent on the particle size used. The catalytic activities were dependent on the pore structure and on the type of add functionality. Typically, the catalysts with high Bronsted acidity (eg. alumina pillared beidellite) were more active than those exhibiting primarily Lewis addity. The relationship between the pore structure of the catalyst and the distribution of monoalkylated products was also investigated. The more microporous catalysts (eg. alumina pillared montmorillonite) afforded higher yields of meta- and para-alkylated isomers than catalysts with little or no micropores (eg. K10 montmorillonite and delaminated Laponite). Coke formation occurred in the micropores and was related to the iron content of the clays.
Novel Synthesis and Structural Analysis of Ferrihydrite

Naturally occurring ferrihydrite is both impure and difficult to isolate, so the numerous applications and interesting properties of ferrihydrite have spurred the development of various synthetic techniques. Nearly all techniques are based on the hydrolysis of an iron salt and require careful control of temperature, pH, and concentration. In this Article, we report a new synthetic method which does not require such control and is perhaps the fastest and simplest route to synthesizing ferrhydrite. XRD, TEM, BET, and chemical purity characterizations show that the chemically pure, 2-line ferrihydrite product consists of crystallites 2-6 nm in diameter which aggregate to form mesoporous, high surface area agglomerates that are attractive candidates for the many adsorption applications of ferrihydrite. X-ray PDF data were also collected for the ferrihydrite product and refined against the hexagonal structural model recently proposed by Michel et al. These analyses suggest that ferrihydrite has a consistent, repeatable structure independent of variation in the synthetic method, water content of the sample, or particle size of the crystallites, and this structure can be adequately described by the proposed hexagonal model.
Asynchronous Event-Driven Particle Algorithms

We present, in a unifying way, the main components of three asynchronous event-driven algorithms for simulating physical systems of interacting particles. The first example, hard-particle molecular dynamics, is well known. We also present a recently developed diffusion kinetic Monte Carlo algorithm, as well as a novel stochastic molecular-dynamics algorithm that builds on the Direct Simulation Monte Carlo. We explain how to effectively combine asynchronous event-driven with classical time-driven or with synchronous event-driven handling. Finally, we discuss some promises and challenges for event-driven simulation of realistic physical systems.
Room-Temperature Ionic Liquids: Slow Dynamics, Viscosity, and the Red Edge Effect

Ionic liquids (ILs) have recently attracted significant attention from academic and industrial sources. This is because, while their vapor pressures are negligible, many of them are liquids at room temperature and can dissolve a wide range of polar and nonpolar organic and inorganic molecules. In this Account, we discuss the progress of our laboratory in understanding the dynamics, spectroscopy, and fluid dynamics of selected imidazolium-based ILs using computational and analytical tools that we have recently developed. Our results indicate that the red edge effect, the non-Newtonian behavior, and the existence of locally heterogeneous environments on a time scale relevant to chemical and photochemical reactivity are closely linked to the viscosity and highly structured character of these liquids.
Late inflation and the moduli problem of sub-millimeter dimensions

Abstract We consider a recent model with sub-millimeter sized extra dimensions, where the field that determines the size of the extra dimensions (the radion) also acts as an inflaton. The radion is also a stable modulus, and its coherent oscillations can potentially overclose the Universe. It has been suggested that a second round of late inflation can solve this problem, however we find that this scenario does not allow for sufficient reheating of the Universe.
Trapping the Tigers: Regulation of Market Entry and the Rule of Law in SE Asia

Abstract Recent research identifies high barriers to registering a business as critical impediments to economic development around the world. Similarly, the lack of credible commitment to the rule of law – especially in the areas of property rights and contract enforcement – is also connected to economic underdevelopment. Scholarship treats these factors as rival explanations for underdevelopment. However, I argue the rule of law is the causal mechanism through which barriers to entry in the marketplace influence economic outcomes. Specifically, I present evidence perceptions of the rule of law in Southeast Asia decline as the legal restrictions on registering a business increase because public officials use their gatekeeping positions to extract rents and raise the costs of formalizing private enterprises. High disincentives to register a business drive entrepreneurs underground, which in turn leaves them vulnerable to extortion or confiscation by public officials and undermines perceptions of the rule of law. I employ pooled cross-sectional time-series data for all countries in SE Asia between 1996 and 2010 to test my theoretical argument. I use Two-Stage Least Squares Instrumental Variables, Time Series, Cross-Sectional and OLS regression models to isolate causal mechanisms and causal directions among my variables. My analyses demonstrate the deleterious effect of legal barriers to entry on the rule of law and provides a new direction for scholarship on the topic.
Syntheses, structure, magnetism, and optical properties of the ordered mixed-lanthanide sulfides γ-LnLn'S3 (Ln = La, Ce; Ln' = Er, Tm, Yb)

γ-LnLn‘S3 (Ln = La, Ce; Ln‘ = Er, Tm, Yb) have been prepared as dark red to black single crystals by the reaction of the respective lanthanides with sulfur in a Sb2S3 flux at 1000 °C. This isotypic series of compounds adopts a layered structure that consists of the smaller lanthanides (Er, Tm, and Yb) bound by sulfide in six- and seven-coordinate environments that are connected together by the larger lanthanides (La and Ce) in eight- and nine-coordinate environments. The layers can be broken down into three distinct one-dimensional substructures containing three crystallographically unique Ln‘ centers. The first of these is constructed from one-dimensional chains of edge-sharing [Ln‘S7] monocapped trigonal prisms that are joined to equivalent chains via edge sharing to yield ribbons. There are parallel chains of [Ln‘S6] distorted octahedra that are linked to the first ribbons through corner sharing. These latter units also share corners with a one-dimensional ribbon composed of parallel chains of [Ln‘S6] ...