cssi/SciSciGPT-SciSciNet huggingface dataset:
Fundamental Properties of the Highly Ionized Plasmas in the Milky Way

The cooling transition temperature gas in the interstellar medium (ISM), traced by the high ions, Si IV, C IV, N V, and O VI, helps to constrain the flow of energy from the hot ISM with T>10{sup 6} K to the warm ISM with T < 2 x 10{sup 4} K. We investigate the properties of this gas along the lines of sight to 38 stars in the Milky Way disk using 1.5-2.7 km s{sup -1} resolution spectra of Si IV, C IV, and N V absorption from the Space Telescope Imaging Spectrograph, and 15 km s{sup -1} resolution spectra of O VI absorption from the Far Ultraviolet Spectroscopic Explorer. The absorption by Si IV and C IV exhibits broad and narrow components while only broad components are seen in N V and O VI. The narrow components imply gas with T < 7 x 10{sup 4} K and trace two distinct types of gas. The strong, saturated, and narrow Si IV and C IV components trace the gas associated with the vicinities of O-type stars and their supershells. The weaker narrow Si IV and C IV components trace gas in the general ISM that is photoionized by the EUVmore » radiation from cooling hot gas or has radiatively cooled in a non-equilibrium manner from the transition temperature phase, but rarely the warm-ionized medium probed by Al III. The broad Si IV, C IV, N V, and O VI components trace collisionally ionized gas that is very likely undergoing a cooling transition from the hot ISM to the warm ISM. The cooling process possibly provides the regulation mechanism that produces (N(C IV)/N(Si IV)) = 3.9 {+-} 1.9. The cooling process also produces absorption lines where the median and mean values of the line widths increase with the energy required to create the ion.« less
Blowup of Smooth Solutions for Relativistic Euler Equations

We study the singularity formation of smooth solutions of the relativistic Euler equations in (3 + 1)-dimensional spacetime for both finite initial energy and infinite initial energy. For the finite initial energy case, we prove that any smooth solution, with compactly supported non-trivial initial data, blows up in finite time. For the case of infinite initial energy, we first prove the existence, uniqueness and stability of a smooth solution if the initial data is in the subluminal region away from the vacuum. By further assuming the initial data is a smooth compactly supported perturbation around a non-vacuum constant background, we prove the property of finite propagation speed of such a perturbation. The smooth solution is shown to blow up in finite time provided that the radial component of the initial ``generalized'' momentum is sufficiently large.
A Cyclotrimerization Route to Cannabinoids

Three members of the cannabinoid class, cannabinol, cannabinol methyl ether, and cannabinodiol, were synthesized using a microwave-mediated [2 + 2 + 2] cyclotrimerization reaction as the key step. This approach provides a high level of synthetic flexibility allowing for the facile synthesis of cannabinoid analogues.
Bosonization and current algebra of spinning strings

Abstract We write down a general geometric action principle for spinning strings in d-dimensional Minkowski space, which is formulated without the use of Grassmann coordinates. Instead, it is constructed in terms of the pull-back of a left invariant Maurer-Cartan form on the d-dimensional Poincare group to the world-sheet. The system contains some interesting special cases. Among them are the Nambu string (as well as, null and tachyonic strings) where the spin vanishes, and also the case of a string with a spin current—but no momentum current. We find the general form for the Virasoro generators, and show that they are first class constraints in the Hamiltonian formulation of the theory. The current algebra associated with the momentum and angular momentum densities are shown, in general, to contain rather complicated anomaly terms which obstruct quantization. As expected, the anomalies vanish when one specializes to the case of the Nambu string, and there one simply recovers the algebra associated with the Poincare loop group. We speculate that there exist other cases where the anomalies vanish, and that these cases give the bosonization of the known pseudoclassical formulations of spinning strings.
Semi-local quantum liquids

Gauge/gravity duality applied to strongly interacting systems at finite density predicts a universal intermediate energy phase to which we refer as a semi-local quantum liquid. Such a phase is characterized by a finite spatial correlation length, but an infinite correlation time and associated nontrivial scaling behavior in the time direction, as well as a nonzero entropy density. For a holographic system at a nonzero chemical potential, this unstable phase sets in at an energy scale of order of the chemical potential, and orders at lower energies into other phases; examples include superconductors, and antiferromagnetic-type states. In this paper we give examples in which it also orders into Fermi liquids of “heavy” fermions. While the precise nature of the lower energy state depends on the specific dynamics of the individual system, we argue that the semi-local quantum liquid emerges universally at intermediate energies through deconfinement (or equivalently fractionalization). We also discuss the possible relevance of such a semi-local quantum liquid to heavy electron systems and the strange metal phase of high temperature cuprate superconductors.
Trade, Foreign Direct Investment, and Growth: Evidence from Transition Economies

Using fixed effects panel data approach, this paper empirically examines the effects of trade and foreign direct investment (FDI) on growth in 13 transition economies of Central and Eastern Europe, and the Baltic region (CEEB). Our analysis suggests that significant positive effect of trade on growth is a robust result for transition economies of this region. In addition, domestic investment appears to be an important determinant of growth. However, in the presence of trade in the growth equation, FDI does not seem to have any significant effect on growth. The estimation of the growth equation without trade renders FDI highly significant suggesting collinearity between trade and FDI. Furthermore, interaction between trade and FDI seems to be important for growth in transition economies. Among other findings, macroeconomic stability as reflected in the rate of inflation and fiscal balance plays a significant role in the growth process.
Gamma Rays from Small Scale Structures on Long Cosmic Strings

The formation of cusps on long cosmic strings is discussed and the probability of cusp formation is estimated. The energy distribution of the gamma-ray background due to cusp annihilation on long strings is calculated and compared to observations. Under optimistic assumptions about the cusp formation rate, we find that strings with a mass per unit length μ less than Gμ=10−14 will have an observable effect. However, it is shown that the gamma-ray bursters cannot be attributed to long ordinary strings (or loops).
X-ray emission from PSR B1800-21, its wind nebula, and similar systems

We detected X-ray emission from PSR B1800-21 (J1803-2137) and its synchrotron nebula with the Chandra X-Ray Observatory. The observed pulsar flux is (1.4 ± 0.2) × 10-14 ergs cm-2 s-1 in the 1-6 keV band. The spectrum can be described by a two-component power law + blackbody (PL + BB) model, suggesting a mixture of thermal and magnetospheric emission. For a plausible nH = 1.4 × 1022 cm-2, the PL component has a slope Γ = 1.4 ± 0.6 and a luminosity L = 4 × 1031(d/4 kpc)2 ergs s-1. The properties of the thermal component (kT = 0.1-0.3 keV, L = 1031-1033 ergs s-1) are very poorly constrained because of the strong interstellar absorption. The compact, 7'' × 4'', inner pulsar wind nebula (PWN), elongated perpendicular to the pulsar's proper motion, is immersed in a fainter asymmetric emission. The observed flux of the PWN is (5.5 ± 0.6) × 10-14 ergs cm-2 s-1 in the 1-8 keV band. The PWN spectrum fits a PL model with Γ = 1.6 ± 0.3, LPWN = 1.6 × 1032(d/4 kpc)2 ergs s-1. The shape of the inner PWN suggests that the pulsar moves subsonically and X-ray emission emerges from a torus associated with the termination shock in the equatorial pulsar wind. The inferred PWN-pulsar properties (e.g., the PWN X-ray efficiency, LPWN/Ė ~ 10-4; the luminosity ratio, LPWN/L = 4; the pulsar wind pressure at the termination shock, ps = 10-9 ergs cm-3) are very similar to those of other subsonically moving Vela-like objects detected with Chandra (LPWN/Ė ~ 10-4.5 to 10-3.5, LPWN/L ~ 5, ps = 10-10 to 10-8 ergs cm-1).
The Dihydropyrone Diels–Alder Reaction: Development and Application to the Synthesis of Highly Functionalized 1-Oxa-4-decalones

Abstract A facile method for the synthesis of highly functionalized 1-oxadecalone derivatives is described via the Diels–Alder reaction of 2,3-dihydro-4-pyrone dienophiles with electron rich dienes. By this process a variety of functional groups and substitution patterns can be incorporated into the oxadecalone framework.
Reliability of metamorphic HEMTs on GaAs substrates

Abstract Metamorphic HEMT (MHEMT) technology enables the growth of high indium content channels on GaAs substrates, giving them the performance of InP HEMTs. MHEMT growth techniques use a graded alloy composition buffer layer structure, permitting channel indium contents exceeding 25% without strain. Potential applications include 40 Gb/s fiber optic receivers as well as LNAs for local multipoint distribution systems and satellite communications. Many such applications place stringent requirements on reliability with Belcore standards requiring 106 h median time to failure (MTTF) at 125 °C for power devices. Satellite applications require a LNA projected failure-free service of 15–30 years, implying approximately 107 h MTTF, at 85 °C. Naturally, one will ask “Is MHEMT technology reliable?” From the results of our ongoing work, we show that MHEMT reliability is similar to that of InP HEMTs with ∼106 h MTTF at 125 °C.
Prediction of plane strain fracture of AHSS sheets with post-initiation softening

Abstract In this investigation, the three-parameter Modified Mohr–Coulomb (MMC) fracture model and the determination of the material parameters are briefly described. The formulation of the post-initiation behavior is proposed by defining both the explicit softening law and the incremental damage evolution law. As opposed to the existing attempts to simulate slant fracture with material weakening before crack formation, softening is assumed to occur only in the post-initiation range. The justification of this assumption can be provided by the interrupted fracture tests, for example, Spencer et al. (2002) . Element deletion with a gradual loss of strength is used to simulate crack propagation after fracture initiation. The main emphasis of the paper is the numerical prediction of slant fracture which is almost always observed in thin sheets. For that purpose, VUMAT subroutines of ABAQUS are coded with post-initiation behavior for both shell elements and plane strain elements. Fracture of flat-grooved tensile specimens cut from advanced high strength steel (AHSS) sheets are simulated by 2D plane strain element and shell element models.
Growth process and crystallographic properties of ammonia-induced vaterite

Metastable vaterite crystals were synthesized by increasing the pH and consequently the saturation states of Ca2+- and CO32−-containing solutions using an ammonia diffusion method. SEM and TEM analyses indicate that vaterite grains produced by this method are polycrystalline aggregates with a final morphology that has a sixfold-symmetry. The primary structure develops within an hour and is almost a spherical assemblage of nanoparticles (5–10 nm) with random orientation, followed by the formation of hexagonal platelets (1–2 μm), which are first composed of nanoparticles and that develop further into single crystals. As determined using transmission electron microscopy, these hexagonal crystallites are terminated by (001) surfaces and are bounded by {110} edges. The hexagonal crystals subsequently stack to form the “petals” (20 μm wide, 1 μm thick) of the final “flower-like” vaterite morphology. The large flakes gradually tilt toward the center as growth progresses so that their positions become more and more vertical, which eventually leads to a depression in the center. Since this sequence encompasses several morphologies observed in previous studies (spheres, hexagons, flowers etc.), they may actually represent different stages of growth rather than equilibrium morphologies for specific growth conditions.
Family Composition and Off-Farm Participation Decisions in Israeli Farm Households

This article studies the relationship between the off-farm participation behavior of farm operators and their spouses and the demographic composition of the household. We focus on farm families without parents, siblings or partners, and examine the effects of the existence of elderly children of the farm couple. We find that both the father and the mother tend to reduce their participation in off-farm work as the number of elderly children rises. This result holds even after controlling for observed characteristics. We also find that the effect of elderly children stems from considerations related to both farm production and household production.
The low power energy aware processing (LEAP)embedded networked sensor system

A broad range of embedded networked sensor (ENS) systems for critical environmental monitoring applications now require complex, high peak power dissipating sensor devices, as well as on-demand high performance computing and high bandwidth communication. Embedded computing demands for these new platforms include support for computationally intensive image and signal processing as well as optimization and statistical computing. To meet these new requirements while maintaining critical support for low energy operation, a new multiprocessor node hardware and software architecture, low power energy aware processing (LEAP), has been developed. The LEAP architecture integrates fine-grained energy dissipation monitoring and sophisticated power control scheduling for all subsystems including sensor subsystems. This paper also describes a new distributed node testbed demonstrating that by exploiting high high energy efficiency components and enabling proper on-demand scheduling, the LEAP architecture may meet both sensing performance and energy dissipation objectives for a broad class of applications.
5-Exo-dig Radical Cyclization of Enediynes: The First Synthesis of Tin-Substituted Benzofulvenes

[reaction: see text] Bu(3)Sn-mediated 5-exo-dig radical cyclization of diaryl enediynes provides a mild and efficient approach to tin-substituted fulvenes. Further synthetic opportunities opened by this process and general factors responsible for the observed regio- and stereoselectivity are outlined.
Photodissociation of RNCS and RSCN (R=H, CH3, C2H5) at 248 and 193 nm: CN product energy distributions

Photodissociation of the molecules RNCS and RSCN (R=H, CH3, and C2H5) was investigated at 248 and 193 nm and the internal energy distributions in the CN resulting from the RS+CN fragmentation channel were probed by laser induced fluorescence. These CN distributions were identical for formation from the isomer pairs in agreement with an excited state isomerization postulated earlier. At 248 nm, all precursors lead to nearly thermal CN rotational distributions with rotational temperatures of approximately 1100 K in v=0 and 800 K in v=1. The vibrational distributions could not be characterized by the same temperatures. At 193 nm, contributions from two apparently different dissociation channels were observed. The CN rotational populations showed a narrow, strongly peaked distribution lying on a broad, approximately statistical distribution. For HNCS, this peak occurs near N=10 suggesting dissociation from an excited state with a linear NCS skeleton. For the alkyl precursors, the peak occurs at very high rota...
Sonoluminescence in neutron stars

Abstract We examine the possibility that the electroweak phase transition that occured in the early universe might be contemporarily occurring in processes in neutron stars. Our conjecture is that adiabatic compression of neutron star matter due to focusing of the energy from a supernova bounce into a very small volume could result in extreme densities and temperatures above 100 GeV. We propose a qualitative scenario for sonoluminescence in neutron stars and discuss possible observable consequences.
Localized resist heating due to electron-beam patterning during photomask fabrication

Localized resist heating effects that occur during electron beam (e-beam) patterning of optical masks can lead to critical dimension (CD) errors. These errors are due to unexpected resist development or underdevelopment, which is related to the temperature history of the resist. Eliminating this source of error requires a knowledge of the localized temperature history and how resist properties are impacted by elevated temperatures. Computer simulations of electron beam patterning of an optical mask can address the temperature history of the localized heating not possible through experimentation. Presented are the results of a study to determine the feasibility of using finite element (FE) analysis to predict these thermal effects. Two models were created to demonstrate its capabilities. The first shows that FE modeling is capable of high spatial resolution temperature profiles. The second demonstrates that FE models can be programmed to run complete patterning simulations.
Postoperative Hypopyon After Intravitreal Bovine Thrombin for Macular Hole Surgery

Purpose: We used intravitreal autologous fibrinogen with bovine thrombin for the surgical closure of macular holes in 60 cases. Methods: Pars plana vitrectomy with separation of the posterior cortical vitreous was performed after air/fluid exchange. One to two drops each of autologous fibrinogen and bovine thrombin (20 to 80 U) were instilled in each patient. Results: Five (8%) of 60 patients developed a hypopyon without unusual pain on the first postoperative day. Inflammation responded to frequent topical corticosteroids within 48 to 72 hours. Conclusion: Postvitrectomy hypopyon after the use of bovine thrombin may represent an immune reaction that must be differentiated from endophthalmitis. We recommend careful observation and frequent topical corticosteroids.
Age and Abundance Discrimination in Old Stellar Populations Using Mid-Ultraviolet Colors

The rest-frame mid-ultraviolet spectral region (2000-3200 A) is important in analyzing the stellar populations of the "red envelope" systems observed at high redshifts. Here we explore the usefulness of the mid-UV for determining ages and abundances of old populations. We work with a theoretical set of low-resolution spectra and broadband colors because tests show that these are at present more realistic than high-resolution models. A mid-UV to optical/IR wavelength baseline provides good separation of population components because the main-sequence turnoff dominates the integrated light between 2500 and 4000 A. Mid-UV spectral features are not sensitive to the dwarf/giant mixture in the population, unlike those in the optical region. We find a 6 mag difference in the mid-UV continuum level (normalized at V) over the metallicity range -1.5 < log(Z/Z☉) < +0.5 and a comparable difference (per unit log t) for ages in the range 4-16 Gyr. Logarithmic derivatives of mid-UV colors with respect to age or metal abundance are 3-10 times larger than for the UBV region. Most of the spectral information on old populations therefore resides below 4000 A. Measurement of a single mid-UV color is capable of placing a strong lower bound on the mean metallicity of an old population. We investigate the capability of UBV and mid-UV broadband colors to separately determine age and abundance, taking into account precision in the color measurements. We find that the mid-UV improves resolution in log t, log Z space by about a factor of 3 for a given observational precision. Contamination by hot, post-He flash evolutionary phases can seriously affect the mid-UV spectra of old populations. A simple estimate shows that contamination can reach over 80% in some cases. However, this is straightforward to remove as long as far-UV measurements are available. We find that extinction should have relatively small effects on parameters derived for old populations from the mid-UV. Finally, we show that a 4 Gyr, solar abundance model based on empirical spectra for nearby stars provides an excellent fit to the mid-UV spectrum of the Local Group elliptical galaxy M32. This indicates that the poorer results obtained from theoretical spectra do arise from limitations of the synthesis models for individual stars.
Relaxation Rates and Collision Integrals for Bose-Einstein Condensates

Near equilibrium, the rate of relaxation to equilibrium and the transport properties of excitations (bogolons) in a dilute Bose-Einstein condensate (BEC) are determined by three collision integrals, Open image in new window, Open image in new window, and Open image in new window. All three collision integrals conserve momentum and energy during bogolon collisions, but only Open image in new window conserves bogolon number. Previous works have considered the contribution of only two collision integrals, Open image in new window and Open image in new window. In this work, we show that the third collision integral Open image in new window makes a significant contribution to the bogolon number relaxation rate and needs to be retained when computing relaxation properties of the BEC. We provide values of relaxation rates in a form that can be applied to a variety of dilute Bose-Einstein condensates.
Efficient Nickel-Catalyzed [2 + 2 + 2] Cycloaddition of CO2 and Diynes

A mild and general route for preparing 2-pyrones from CO2 and diynes is described. Under only 1 atm of CO2, excellent yields of pyrone are obtained using catalytic amounts of Ni(COD)2 and imidazolylidene ligand, IPr. In addition, stoichiometric reactions between the isolated complex Ni(IPr)2, diynes, and CO2 suggest that the pathway involves initial reaction with CO2 as the key step.
Functionalized olefin cross-coupling to construct carbon–carbon bonds

Carbon-carbon (C-C) bonds form the backbone of many important molecules, including polymers, dyes and pharmaceutical agents. The development of new methods to create these essential connections in a rapid and practical fashion has been the focus of numerous organic chemists. This endeavour relies heavily on the ability to form C-C bonds in the presence of sensitive functional groups and congested structural environments. Here we report a chemical transformation that allows the facile construction of highly substituted and uniquely functionalized C-C bonds. Using a simple iron catalyst, an inexpensive silane and a benign solvent under ambient atmosphere, heteroatom-substituted olefins are easily reacted with electron-deficient olefins to create molecular architectures that were previously difficult or impossible to access. More than 60 examples are presented with a wide array of substrates, demonstrating the chemoselectivity and mildness of this simple reaction.
Rotational Velocities of Low-Mass Stars in the Pleiades and Hyades

We have obtained high-resolution spectra of 89 M dwarf members of the Pleiades and Hyades and have derived radial velocities, Hα equivalent widths, and spectroscopic rotational velocities for these stars. Typical masses of the newly observed Pleiades and Hyades stars are ~0.4 M⊙ and ~0.2 M⊙, respectively. We combine our new observations with previously published data to explore the rotational evolution of young stars with M ≤ 0.4 M⊙. The average rotation rate in the Hyades (age 600 Myr) is about 0.4 times that in the Pleiades (110 Myr), and the mean equivalent widths of Hα are also lower. As found in previous studies, the correlation between rotation and chromospheric activity is identical in both clusters, implying that the lower activity in the Hyades is a result of the lower rotation rates. We show that a simple scaling of the Pleiades rotational distribution for M ≤ 0.4 M⊙, corrected for the effects of structural evolution, matches that of the Hyades if the average angular momentum loss from the Pleiades to the Hyades age is factor of ≈6. This suggests that the distribution of initial angular momenta and disk-locking lifetimes for the lowest mass stars was similar in both clusters. We argue that this result provides further evidence for a saturation of the angular momentum loss rate at high rotational velocities.
User misconceptions of information retrieval systems

We report results of an investigation where thirty subjects were observed performing subject-based search in an online catalog system. The observations have revealed a range of misconceptions users have when performing subject-based search. We have developed a taxonomy that characterizes these misconceptions and a knowledge representation which explains these misconceptions. Directions for improving search performance are also suggested.
Impact of cosmic rays on Population III star formation

We explore the implications of a possible cosmic-ray (CR) background generated during the first supernova explosions that end the brief lives of massive Population III stars. We show that such a CR background could have significantly influenced the cooling and collapse of primordial gas clouds in minihaloes around redshifts of z ∼15-20, provided the CR flux was sufficient to yield an ionization rate greater than about 10- 19 s -1 near the centre of the minihalo. The presence of CRs with energies ≤10 7 eV would indirectly enhance the molecular cooling in these regions, and we estimate that the resulting lower temperatures in these minihaloes would yield a characteristic stellar mass as low as ∼10M⊙. CRs have a less-pronounced effect on the cooling and collapse of primordial gas clouds inside more massive dark matter haloes with virial masses (≥10 8 M ⊙ at the later stages of cosmological structure formation around z ∼ 10-15. In these clouds, even without CR flux the molecular abundance is already sufficient to allow cooling to the floor set by the temperature of the cosmic microwave background.
The Legal Consequences of Mandating High Stakes Decisions Based on Low Quality Information: Teacher Evaluation in the Race-to-the-Top Era.

In this article, we explain how overly prescriptive, rigid state statutory and regulatory policy frameworks regarding teacher evaluation, tenure and employment decisions outstrip the statistical reliability and validity of proposed measures of teaching effectiveness. We begin with a discussion of the emergence of highly prescriptive state legislation regarding the use of student testing data within teacher evaluation systems, specifically for purposes of making employment decisions. Next, we explain the most problematic features of those policies, which include a) requirements that test-based measures constitute fixed, non-negotiable weight in final decisions, b) that test-based measures are used to place teachers into categories of effectiveness by applying numerical cutoffs beyond the precision or accuracy of the available data, and c) that professional judgment is removed from personnel decisions by legislating (or regulating) specific actions be taken when teachers fall into certain performance categories. In the subsequent section, we point out that different types of measures are being developed and implemented across states, and we explain that while value-added metrics in particular are, in fact designed to estimate a teacher’s effect on student outcomes, descriptive growth percentile measures are not designed for making such inference and thus have no place in making determinations regarding teacher effectiveness. We also explain that, due to the properties of value-added estimates, they have no place in making high-stakes decisions based on rigid policy frameworks like those described herein. We evaluate the legal implications of rigid reliance on measures of teaching effectiveness that a) lack reliability and b) may be entirely invalid.
Permanent magnetic moment in mesoscopic metals with spin–orbit interaction

Abstract We argue that at zero temperature an isolated metal particle (or an AB ring) with spin–orbit interaction and odd number of electrons will have a permanent magnetic moment, even in zero magnetic field (flux). In a zero-field-cooled state both the direction and the magnitude of the moment varies from particle to particle and averages to zero. In a field-cooled state it averages to ∼ μ B ( k F l) 1/2 . We argue that the permanent moment is due to an uncompensated electron in the last occupied (Fermi) level. We introduce an effective single-electron Hamiltonian which accounts for spin–orbit coupling.
Is there cyclical bias in bank holding company risk ratings

Abstract This paper examines whether bank holding company (BHC) risk ratings are asymmetrically assigned or biased over business cycles from 1986 to 2003. In a model of ratings determination which accounts for bank characteristics, financial market conditions, past supervisory information, and aggregate macro-economic factors, we find that bank exam ratings exhibit inter-temporal characteristics. First, exam ratings exhibit some evidence of examiner bias for several periods analyzed. When the business cycle turns, examiners sometime depart from standards that they set during the previous phases of the cycle. However, this bias is not widespread or systematic. Second, exam ratings exhibit some inertia. Our results suggest that examiners rate on the side of not changing (rather than upgrading or downgrading) an institution’s exam rating. Third, we find robust evidence of a secular trend towards more stringent examination BHC ratings standards over time.
Synthesis of fluorine-substituted anthraquinones and aza-anthraquinones

Abstract Using 1,4-dipolar-aryne cycloaddition methodology, a convenient, short synthesis of several fluoroanthraquinones is presented which involves the reaction of haloarenes and 3-cyanophthalides in the presence of lithium diisopropylamide (LDA) in tetrahydrofuran (THF). The fluorine substituent(s) can be introduced by using fluorine-substituted haloarenes and/or 3-cyanophthalides. Similarly, fluorine-substituted pyridines can be repared by treating fluorine-substituted cyanophthalides and halopyridines in the presence of lithium diisopropylamide.
Quantitative measurements of subcritical debonding of Cu films from glass substrates

A driver film method, in which a highly stressed overlayer is deposited to de-adhere a target film from a substrate, was developed to study the subcritical debonding behavior of Cu films from glass substrates. The driving force for debonding along Cu/glass interfaces was varied by depositing Cr overlayers to a range of thicknesses. One-dimensional crack growth was achieved by using C release layers and cutting strips from blanket films. Crack velocities, v, were measured and a wide strip solution was developed to obtain strain energy release rates, G. The Cu/Cr strips delaminated in a highly reproducible way, generating v-G plots similar to those seen in stress-corrosion cracking of bulk glass. Small variations in the amount of oxygen incorporated into the films during deposition strongly affected delamination rates. A reaction rate model for subcritical cracking by hydroxylation of the surfaces suggests that changes in oxygen content change the density of strong Cu-O-Si bonds across the interface.
Global minimizers for free energies of subcritical aggregation equations with degenerate diffusion

Abstract We prove the existence of global minimizers of a class of free energies related to aggregation equations with degenerate diffusion on R d . Such equations arise in mathematical biology as models for organism group dynamics which account for competition between the tendency to aggregate into groups and nonlinear diffusion to avoid overcrowding. The existence of non-trivial stationary solutions with minimal energy representing coherent groups in R d is therefore of interest. A scaling criticality that measures the balance between the diffusive and aggregative forces as mass spreads is shown to govern the existence and non-existence of global minimizers. The primary difficulty confronted here is the inability to verify strict subadditivity conditions for biologically relevant problems which violate homogeneity-type assumptions known to be sufficient. To recover, we show that sufficiently degenerate diffusion provides a weaker condition from which tightness of symmetrized infimizing sequences can be recovered, even when the nonlocal attractive force is extremely weak.
A second step toward the polynomial hierarchy

Abstract Some of the questions posed by Baker et al. [1] are here answered. The principal result is that there exists a recursive oracle for which the relativized polynomial hierarchy exists through the second level; that is, there is a recursive set B such that Σ 2 P,B ≠ Π 2 P,B . It follows that Σ 2 P,B ⊊ Σ 3 P,B .
Graph-Based Discriminative Learning for Location Recognition

Recognizing the location of a query image by matching it to an image database is an important problem in computer vision, and one for which the representation of the database is a key issue. We explore new ways for exploiting the structure of an image database by representing it as a graph, and show how the rich information embedded in such a graph can improve bag-of-words-based location recognition methods. In particular, starting from a graph based on visual connectivity, we propose a method for selecting a set of overlapping subgraphs and learning a local distance function for each subgraph using discriminative techniques. For a query image, each database image is ranked according to these local distance functions in order to place the image in the right part of the graph. In addition, we propose a probabilistic method for increasing the diversity of these ranked database images, again based on the structure of the image graph. We demonstrate that our methods improve performance over standard bag-of-words methods on several existing location recognition datasets.
Regio- and diastereoselectivity of enol ether formation by 1,4-sigmatropic shifts of hydrogen in carbonyl ylides

Abstract Treatment of aliphatic ketones with ethyl diazoacetate in the presence of a catalyst results in the regio- and (where appropriate) diastereoselective formation of enol ethers which arise by an intramolecular 1,4-hydrogen shift from an intermediate carbonyl ylide.
Efficacy of olanzapine in combination with valproate or lithium in the treatment of mania in patients partially nonresponsive to valproate or lithium monotherapy.

Background A 6-week double-blind, randomized, placebo-controlled trial was conducted to determine the efficacy of combined therapy with olanzapine and either valproate or lithium compared with valproate or lithium alone in treating acute manic or mixed bipolar episodes. Methods The primary objective was to evaluate the efficacy of olanzapine (5-20 mg/d) vs placebo when added to ongoing mood-stabilizer therapy as measured by reductions in Young Mania Rating Scale (YMRS) scores. Patients with bipolar disorder (n = 344), manic or mixed episode, who were inadequately responsive to more than 2 weeks of lithium or valproate therapy, were randomized to receive cotherapy (olanzapine + mood-stabilizer) or monotherapy (placebo + mood-stabilizer). Results Olanzapine cotherapy improved patients' YMRS total scores significantly more than monotherapy (−13.11 vs −9.10; P = .003). Clinical response rates (≥50% improvement on YMRS) were significantly higher with cotherapy (67.7% vs 44.7%; P P DSM-IV mixed episode; HAMD-21 score of ≥20 at baseline), olanzapine cotherapy improved HAMD-21 scores by 10.31 points compared with 1.57 for monotherapy ( P Conclusion Compared with the use of valproate or lithium alone, the addition of olanzapine provided superior efficacy in the treatment of manic and mixed bipolar episodes.
Spin-torque ferromagnetic resonance measurements of damping in nanomagnets

The authors directly measure the magnetic damping parameter α in thin-film CoFeB and Permalloy (Py) nanomagnets at room temperature using a recently developed ferromagnetic resonance technique where the precessional mode of an individual nanomagnet can be excited by microwave-frequency spin-transfer torque and detected by the giant magnetoresistance effect. The authors obtain αCoFeB=0.014±0.003 and αPy=0.010±0.002, values comparable to measurements for extended thin films, establishing that patterned nanomagnets can exhibit magnetic damping that is consistent with that of unpatterned bulk material.
The limitations of using vertical cutoff rigidities determined from the IGRF magnetic field models for computing aircraft radiation dose

Vertical cutoff rigidities derived from the International Geomagnetic Reference Fields (IGRF) are normally used to compute the radiation dose at a specific location and to organize the radiation dose measurements acquired at aircraft altitudes. This paper presents some of the usually ignored limits on the accuracy of the vertical cutoff rigidity models and describes some of the computational artifacts present in these models. It is noted that recent aircraft surveys of the radiation dose experienced along specific flight paths is sufficiently precise that the secular variation of the geomagnetic field is observable.
Designs and technologies for future planetary power systems

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Optimal reduced-order observer-estimators

A unified approach to designing reduced-order observer-estimators is presented. Specifically, an attempt is made to design a reduced-order estimator satisfying an observation constraint which involves a prespecified, possibly unstable subspace of the system dynamics and which also yields reduced-order estimates of the remaining subspace. The results are obtained by merging the optimal projection approach to reduced-order estimation of D.S. Bernstein and D.C. Hyland (IEEE Trans. Autom. Control, vol.AC-30, p.583-5, 1985) with the subspace-observer results of the authors (Proc. IEEE Conf. on Decision and Control, p.2364-6, Dec. 1988). A salient feature of this theory is the treatment of unstable dynamics within reduced-order stable-estimation theory. In contrast to the standard full-order estimation problem involving a single algebraic Riccati equation, the solution to the reduced-order observer-estimator problem involves an algebraic system of four equations consisting of one modified Riccati equation and three modified Lyapunov equations coupled by two distinct oblique projections. >
Collaborative planning, forecasting and replenishment (CPFR) as a relational contract: an incomplete contracting perspective

This paper analyses collaborative planning, forecasting and replenishment (CPFR) from an incomplete contracting perspective. In the absence of economic incentive problems, CPFR enables trading partners to improve operational efficiency through a structured process of learning by both sharing and utilising information across firm-level boundaries. From a review of the incomplete contracts literature and a case study of the CPFR arrangement between P&G and Wal-Mart, this paper posits CPFR as a relational contract for managing economic incentive problems, which can arise in a vertical supply relationship due to transaction costs, agency costs, and relative bargaining positions. Theoretical propositions are developed regarding when this IT-supported intermediate form of vertical contracting is preferred to other governance modes and how CPFR can be an effective relational contract to support economic exchange and to create intellectual capital between trading partners. With efficient vertical coordination and enhanced specialisation incentives for mutual commitment, CPFR allows contracting parties to avoid the difficulties of formal contracting while realising the benefits that would be anticipated from vertical financial ownership.
Simplified method for predicting photovoltaic array output

Abstract A simplified procedure for predicting the long term, monthly average electrical output of photovoltaic arrays is presented. It is restricted to passively cooled, max-power tracked arrays, but is applicable to both south facing, fixed flat arrays and 2-D tracked concentrators. The procedure combines basic parameters characterizing the array with the local monthly mean temperature and the monthly KT (ratio of the total radiation on the horizontal to the extraterrestrial radiation) to yield a monthly average array efficiency which, when multiplied by the monthly array insolation gives the electrical energy output.
A Photoionization Model for the Soft X-Ray Spectrum of NGC 4151

We present an analysis of archival data from multiple XMM-Newton observations of the Seyfert 1 galaxy NGC 4151. Spectral data from the RGS instruments reveal several strong soft X-ray emission lines, chiefly from hydrogen-like and helium-like oxygen, nitrogen, neon, and carbon. Radiative recombination continua (RRC) from oxygen and carbon are also detected. Our analysis suggests that the emission data are consistent with photoionization. Using the Cloudy photoionization code, we found that, while a two-component, high column density model (1023 cm -2) with low covering factor proved adequate in reproducing all detected Lyman series lines, it proved insufficient in modeling the He-like triplets observed (neon, oxygen, and nitrogen). If resonance line data were ignored, the two-component model was sufficient to match flux from intercombination and forbidden lines. However, with the inclusion of resonance line data, He-like triplets could no longer be modeled with only two components. We found that observed oxygen G and R ratios in particular were anomalous in the parameter space investigated. We investigated, and were forced to dismiss, the possibility that a third, purely collisional component could be responsible for enhanced resonance line contributions. We succeeded in modeling the observed spectrum with the addition of a third, lower column density (1020.5 cm-2) component with nonzero microturbulence and high covering factor. While sufficient to reproduce observed soft X-ray flux, our model has certain shortcomings, particularly in a less-than-ideal visual fit to the line profile. Two of the three emission model components bear similarities to components determined by Kraemer et al. in their 2005 study of NGC 4151 absorption spectra.
LHC and dark matter signals of improved naturalness

The Standard Model Higgs suffers from the hierarchy problem, typically implying new states within the reach of the LHC. If the Higgs is very heavy ( ~ 500 GeV) the states that cutoff the quadratic divergence may be beyond the reach of the LHC. However, in this case precision electroweak data require the Standard Model to be augmented with new states at the electroweak scale. We study a very simple model, with no new colored states, that allows a heavy Higgs whilst remaining consistent with experiments, and yielding the correct dark matter abundance. We investigate the possibilities for its discovery at the LHC and future dark matter detection experiments.
Long lived fourth generation and the Higgs

A chiral fourth generation is a simple and well motivated extension of the standard model, and has important consequences for Higgs phenomenology. Here we consider a scenario where the fourth generation neutrinos are long lived and have both a Dirac and Majorana mass term. Suchneutrinoscanbeaslightas40GeVandcanbethedominant decay mode of the Higgs boson for Higgs masses below the W-boson threshold. We study the effect of the Majorana mass term on the Higgs branching fractions and reevaluate the Tevatron constraints on the Higgs mass. We discuss the prospects for the LHC to detect the semi-invisible Higgs decays into fourth generation neutrino pairs. Under the assumption that the lightest fourth generation neutrino is stable, its thermal relic density can be up to 20% of the observed dark matter density in the universe. This is in agreement with current constraints on the spin dependent neutrino-neutron cross section, but can be probed by the next generation of dark matter direct detection experiments.
Noether Charges for self‐interacting quantum field theories in curved spacetimes with a Killing‐vector

We consider self-interacting, perturbative quantum field theory in a curved spacetime background with a Killing vector field. We show that the action of this spacetime symmetry on interacting field operators can be implemented by a Noether charge which arises as a surface integral over the time-component of the interacting Noether current-density associated with the Killing field. The proof of this involves the demonstration of a corresponding set of Ward identities. Our work is based on the perturbative construction by Brunetti and Fredenhagen (Commun.Math.Phys. 208 (2000) 623-661) of self-interacting quantum field theories in general globally hyperbolic spacetimes.
An Introduction to the pre-CME Corona

Coronal mass ejections provide a gateway to understanding the physics of energy release and conversion in the solar corona. While it is generally accepted that the energy required to power a CME is contained in the pre-eruption coronal magnetic field, the pre-CME state of that field and the conditions leading up to the release of the magnetic energy are still not entirely clear. Recent studies point to various phenomena which are common to many, if not all, CME events, suggesting that there may be identifiable characteristics of the pre-CME corona which signal the impending eruption. However, determining whether these phenomena are necessary or even sufficient has yet to be achieved. In this paper we attempt to summarize the state of the solar corona and its evolution in the build up to a CME.
Emergence of Endogenous Legal Institutions: Property Rights and Community Governance in the Italian Alps

This article examines changes in institutions that protected property rights in the Alps between the thirteenth and the nineteenth century and, in particular, alternative management systems adopted for the common pastures and forests in about 200 communities. Over time, private-order institutions in the form of charters replaced informal arrangements sustained by the long-run interaction among villagers. Although costly to run, the charters accomplished several tasks that increased resource use efficiency.