cssi/SciSciGPT-SciSciNet huggingface dataset:
Evolution of forward multi-particle spectrometers at storage rings☆

Abstract We review the evolution of forward multi-particle spectrometers at storage rings. The first such spectrometers at a proton-proton colliding beam machine were Experiments R603 and R608 which ran at the CERN ISR during 1973–1974 and 1980–1983, respectively. A microvertex detector capability was developed at CERN in the P238 test-experiment at the SPS-Collider in 1990. LHC-B is a third-generation version planned for the CERN Large Hadron Collider, which will be dedicated to the study of CP violation in B-meson decays and other rare phenomena. Other experiments, in which a stored beam interacts with an (internal) fixed target, were Experiment UA6 at the SPS-Collider (gas-jet target) during 1984–1990 and, under construction at DESY, the HERA-B experiment at the HERA proton storage ring, which will run with wire targets in the proton beam halo.
An exploratory study of frequent pain measurement in a cancer clinical trial

The ideal methodology for quality of life (QOL) measurement in cancer clinical trials matches the evaluation to the anticipated outcomes, thereby increasing the likelihood that clinically relevant changes are captured. The present study explored the importance of such methodological ‘tailoring’ in a phase II trial of paclitaxel and recombinant human granulocyte-colony stimulating factor (rhG-CSF) for metastatic breast cancer. Prior to the trial, clinical observation suggested that frequent short-lived episodes of pain might occur during this treatment regimen. Twenty-one patients provided longitudinal data for at least three cycles of chemotherapy. To assess transient pain, aroutine QOL assessment at baseline and every third cycle was supplemented with pain measurements twice weekly. The interval assessment included a multidimensional QOL instrument (Functional Living Index-Cancer) and measures of psychological state (Rand Mental Health Inventory), symptom distress (Memorial Symptom Assessment Scale), and performance status (Karnofsky Performance Status Score). The frequent pain measurements were acquired using visual analogue and categorical scales for pain intensity (Memorial Pain Assessment Card). From baseline to the end of cycle three, global pain scores declined and the results on other QOL measures were variable. The data obtained using these measures did not reveal the existence of episodic pains. In contrast, the twice weekly pain measurements clearly demonstrated transient severe pains in approximately half the patients. These data highlight the importance of specific measurement of troubling symptoms or other relevant QOL concerns at clinically appropriate intervals during the routine QOL assessment of clinical trials. The additional burden involved in these assessments is warranted if the information derived is highly relevant, would not be adequately captured otherwise and could improve therapy.
The Reflection of X-Rays by Plane Surfaces

The reflection of the $K{\ensuremath{\alpha}}_{1}$ radiation of molybdenum by plane surfaces of glass and quartz and by sputtered films of nickel, platinum, and silver has been investigated. It was found that the critical angle of reflection of nickel was smaller for transparent films than for opaque ones. The critical angles for both nickel and platinum were lower than the values calculated from the electron theory. The experimental value for the critical angle of silver agreed with the theoretical within the limits of error of the experiment. Doan has found experimental values of the critical angle for films of a number of metals that agree with those predicted by the theory, and Edwards has obtained similar results using solid reflectors. If it is to be granted that the theory does hold true in the case of nickel and platinum, too, it is necessary to assume that the densities of sputtered films of nickel and platinum are less than those of the metals. Further it must be assumed that in the case of nickel the density varies with the thickness of the film, being smaller for the thinner films.The observed critical angle for quartz was smaller than the theoretical value, as though the surface density was less than the average density. Both glass and quartz surfaces showed a weak residual reflection beyond the critical angles, of a type that was not present in the sputtered films. The phenomenon may be caused by irregular densities over the surface due possibly to the polishing or to the heterogeneous composition of the two substances.
Growth and characterization of very long wavelength type-II infrared detectors

We report on the growth and characterization of type-II IR detectors with a InAs/GaSb superlattice active layer in the 15-19 micrometers wavelength range. The material was grown by molecular beam epitaxy on semi-insulating GaAs substrates. The material was processed into photoconductive detectors using standard photolithography, dry etching, and metalization. The 50 percent cut-off wavelength of the detectors is about 15.5 micrometers with a responsivity of 90mA/W at 80K. The 90 percent-10 percent cut-off energy width of the responsivity is only 17meV which is an indication of the uniformity of the superlattices. These are the best reported values for type-II superlattices grown on GaAs substrates.
Carbon-carbon bond formation under aqueous reaction conditions using sulfonium and selenonium salt electrophiles

Methylation of relatively acidic (pKa<13) carbon nucleophiles occurs at neutral pH in aqueous media using suitably substituted methyl sulfonium and selenonium salt electrophiles.
A cytogenetic model predicts relapse risk and survival in patients with acute myeloid leukemia undergoing hematopoietic stem cell transplantation in morphologic complete remission

Abstract Up to 30% of patients with acute myeloid leukemia (AML) and abnormal cytogenetics have persistent cytogenetic abnormalities (pCytAbnl) at morphologic complete remission (mCR). We hypothesized that the prognostic significance of pCytAbnl in patients undergoing allogeneic hematopoietic stem cell transplantation (HSCT) in mCR varies with cytogenetic risk group. We analyzed the data on 118 patients with AML and abnormal cytogenetics who underwent HSCT in mCR, and developed a risk stratification model based on pCytAbnl and cytogenetic risk group. The model distinguished three groups of patients (P
Multiple-Predictor Regressions: Hypothesis Testing

We propose a new hypothesis-testing method for multipredictor regressions in small samples, where the dependent variable is regressed on lagged variables that are autoregressive. The new test is based on the augmented regression method (Amihud and Hurvich, 2004), which produces reduced-bias coefficients and is easy to implement. The method's usefulness is demonstrated by simulations and by testing a model where stock returns are predicted by two variables, income-to-consumption and dividend yield.
Medical Management of Patients With Brain Tumors

Patients with brain tumors require meticulous attention to medical issues resulting from their disease or its therapy. The following specific issues are the ones most frequently arising in the purview of neurologists: (1) Vasogenic edema: Corticosteroids should be used in divided doses in the minimum amount required to control symptoms and should be tapered as quickly as possible. Some patients may require long-term steroid supplementation, and symptoms of adrenal insufficiency should be investigated with 8 am cortisol measurement and treated with appropriate repletion. (2) Seizures: Patients with brain tumors should receive antiepileptic drugs only if they have had seizures, and the drugs should be chosen to minimize cognitive effects and interactions with concurrently administered chemotherapy. Levetiracetam is an excellent choice for patients with partial seizures and is available both orally and parenterally. Lamotrigine is another reasonable choice but requires slow titration. (3) Venous thromboembolism: All brain tumor patients should receive perioperative venous thrombosis prophylaxis with compression boots and enoxaparin or dalteparin. Lifelong treatment with low molecular weight heparinoids or warfarin is required for those developing venous thromboembolism. (4) Other problems: Long-term survivors of brain tumors should be monitored indefinitely for cognitive problems, endocrine dysfunction, and development of secondary neoplasms. Modafinil can improve mood and attention impairments.
The next breakthrough in phonon-mediated superconductivity

Abstract If history teaches us anything, it is that the next breakthrough in superconductivity will not be the result of surveying the history of past breakthroughs, as they have almost always been a matter of serendipity resulting from undirected exploration into new materials. Still, there is reason to reflect on recent advances, work toward higher T c of even an incremental nature, and recognize that it is important to explore avenues currently believed to be unpromising even as we attempt to be rational. In this paper we look at two remarkable new unusually high temperature superconductors (UHTS), MgB 2 with T c = 40 K and (in less detail) high pressure Li with T c = 20 K, with the aim of reducing their unexpected achievements to a simple and clear understanding. We also consider briefly other UHTS systems that provide still unresolved puzzles; these materials include mostly layered structures, and several with strongly bonded C–C or B–C substructures. What may be possible in phonon-coupled superconductivity is reconsidered in the light of the discussion.
THE AZIMUTH STRUCTURE OF NUCLEAR COLLISIONS — I

We describe azimuth structure commonly associated with elliptic and directed flow in the context of 2D angular autocorrelations for the purpose of precise separation of so-called nonflow (mainly minijets) from flow. We extend the Fourier-transform description of azimuth structure to include power spectra and autocorrelations related by the Wiener–Khintchine theorem. We analyze several examples of conventional flow analysis in that context and question the relevance of reaction plane estimation to flow analysis. We introduce the 2D angular autocorrelation with examples from data analysis and describe a simulation exercise which demonstrates precise separation of flow and nonflow using the 2D autocorrelation method. We show that an alternative correlation measure based on Pearson's normalized covariance provides a more intuitive measure of azimuth structure.
On the time required to sum n semigroup elements on a parallel machine with simultaneous writes

Abstract Suppose we have a completely-connected network of random-access machines which communicate by reading and writing data from their neighbours, with simultaneous reads and writes allowed. In the case of write conflicts, we allow any protocol which results in one of the competing values being written into the target register. We consider the semigroup summation problem, that is, the problem of summing n semigroup elements. If the semigroup is finite, we find that it can be solved in time ( log n log log n using only n processors, regardless of the details of the write-conflict resolution scheme used. In contrast, we show that any parallel machine for solving the summation problem for infinite cancellative semigroups must take time ⌈log3 n⌉, again, regardless of the details of the conflict resolution scheme. We give an example where it is possible to sum n ‘polynomial-sized’ elements in less than ⌈log3 n⌉ time using only polynomially many processors. We are also able to show that such a machine must obey the ⌈log3 n⌉ lower bound for elements which are only polynomially larger. Our upper bounds are for a machine with a reasonable local instruction set, whilst the lower bounds are based on a communication argument, and thus hold no matter how much computational power is available to each processor. Similar results hold for a parallel machine whose processors communicate via a shared memory.
GK-dimension of birationally commutative surfaces

Let k be an algebraically closed field, let K/k be a finitely generated field extension of transcendence degree 2, let σ ∈ Aut k (K), and let A ⊆ Q = K[t; σ] be an N-graded subalgebra with dim k A n 0. Then if A is big enough in Q in an appropriate sense, we prove that GK A = 3,4,5, or oo, with the exact value depending only on the geometric properties of σ. The proof uses techniques in the birational geometry of surfaces which are of independent interest.
Preparation of E-(1,2-difluoro-1,2-ethenediyl)bis(tributylstannane)

Abstract Chlorotrifluoroethene is converted in situ to [F 2 C CFSiMe 3 ]. The crude [F 2 C CFSiMe 3 ] solution is reduced with lithium aluminum hydride to (HFC CFSiMe 3 ), which (without isolation) is converted to ( Z )-HFC CFSnBu 3 . Subsequent metallation and trapping of the vinyllithium reagent with Bu 3 SnCl gives ( E )-Bu 3 SnCF CFSnBu 3 in 73% overall yield. Only two isolation steps are required and the use of Me 3 SiCl and F 2 C CFCl provides a cheap, economical route to this useful synthon.
An X-ray study of domain structure and stress in Pd2Si films at Pd-Si interfaces

The domain structures of palladium and Pd2Si as well as their crystallographic relationship to the silicon substrates were determined on Si(111) and Si(100) samples by mapping X-ray diffraction pole figures. X-ray diffraction topography and rocking curve measurements were carried out for the silicon substrates in order to detect the presence of elastic and/or plastic deformation in the substrates caused by silicide formation. The stresses in the silicide films were determined from the bending of the silicon substrates using X-ray diffraction techniques.
Astrometric Discovery of GJ 802b: In the Brown Dwarf Oasis?

The Stellar Planet Survey is an ongoing astrometric search for giant planets and brown dwarfs around a sample of ~30 M dwarfs. We have discovered several low-mass companions by measuring the motion of our target stars relative to their reference frames. The lowest mass discovery thus far is GJ 802b, a companion to the M5 dwarf GJ 802A. The orbital period is 3.14 +/-0:03 yr, the system mass is 0:214 +/- 0:045 M(circled dot operator), and the semimajor axis is 1:28+/- 0:10 AU or 81 + 6 mas. Imaging observations indicate that GJ 802b is likely to be a brow with the astrometrically determined mass 0:058 +/- 0:021 M(circled dot operator) (1 (sigma) limits). The remaining uncertainty in the orbit is the eccentricity that is now loosely constrained. We dis the system age limits the mass and the prospects of further narrowing the mass range when e is more precisely determined.
Detection of Low-Hard State Spectral and Timing Signatures from the Black Hole X-Ray Transient XTE J1650–500 at Low X-Ray Luminosities

Using the Chandra X-Ray Observatory and the Rossi X-Ray Timing Explorer, we have studied the black hole candidate (BHC) X-ray transient XTE J1650-500 near the end of its 2001-2002 outburst after its transition to the low-hard state at X-ray luminosities down to L = 1.5 × 1034 ergs s-1 (1-9 keV, assuming a source distance of 4 kpc). Our results include a characterization of the spectral and timing properties. At the lowest sampled luminosity, we used an 18 ks Chandra observation to measure the power spectrum at low frequencies. For the three epochs at which we obtained Chandra/RXTE observations, the 0.5-20 keV energy spectrum is consistent with a spectral model consisting of a power law with interstellar absorption. We detect evolution in the power-law photon index from Γ = 1.66 ± 0.05 to 1.93 ± 0.13 (90% confidence errors), indicating that the source softens at low luminosities. The power spectra are characterized by strong (20%-35% fractional rms) band-limited noise, which we model as a zero-centered Lorentzian. Including results from an RXTE study of XTE J1650-500 near the transition to the low-hard state by Kalemci and coworkers, the half-width of the zero-centered Lorentzian (roughly where the band-limited noise cuts off) drops from 4 Hz at L = 7 × 1036 ergs s-1 (1-9 keV, absorbed) to 0.067 ± 0.007 Hz at L = 9 × 1034 ergs s-1 to 0.0035 ± 0.0010 Hz at the lowest luminosity. While the spectral and timing parameters evolve with luminosity, it is notable that the general shapes of the energy and power spectra remain the same, indicating that the source stays in the low-hard state. This implies that the X-ray-emitting region of the system likely keeps the same overall structure, while the luminosity changes by a factor of 470. We discuss how these results may constrain theoretical black hole accretion models.
The Storage of Potatoes and the Maine Potatoes Futures Market

The relationship between the storage of potatoes and the carrying charges reflected on the futures market for Maine potatoes gives rise to a situation in which the observed facts do not seem to agree with the accepted theory. The theory regarding intertemporal price relationships based on the work of Brennan, Telser, and Working establishes that the difference between the current price and the expected price of a storable commodity must be equal to the marginal cost of storage minus the convenience yield. The relationship between the amount of a commodity held in storage and the equality of the marginal cost of storage with the temporal price spread gives rise to a supply of storage curve. As estimated by Brennan, Telser, and Working, this supply of storage curve slopes upward to the right. More storage will be supplied at a high return per unit and less storage at a low return per unit stored. The carrying charges reflected on the Maine potatoes futures market seemingly contradict the theory of the price of storage in two respects. First, the spreads between futures, which establish a return to storage, sometimes appear to greatly exceed any typically plausible cost of storage. On 1 March 1976, the March future for Maine potatoes sold for $8.35 per hundredweight, whereas the May future was selling for $12.63 per hundredweight. The return to storing potatoes for two months was $4.28 per hundredweight. Second, the relationship between the level of potato stocks and the carrying charge appears to be the opposite of that previously estimated for commodities with continuous inventories. For potatoes, the seasonal pattern associates large stocks with a narrow carrying charge and small stocks with a wide carrying charge. The level of potato inventories and the spread on the futures market produce a relationship that slopes downward to the right. The fall potato crop accounts for over 75% of annual U.S. production and in recent years has been about 84% of the total. Fall crop potatoes are stored for consumption over a sevenor eight-month period. However, potatoes cannot be effectively stored for a whole year, since they are semiperishable. Potatoes, therefore, give rise to a discontinuous inventory situation. The task of intertemporal allocation is more difficult for a discontinuous inventory commodity. Potato prices must be established during the storage season with the objective of exhausting the supply of potatoes in storage coincidently with the availability of spring and early summer potatoes (Gray). Potato storage is conducted not by merchandising or storage specialists but primarily by growers. The primary requirements of a potato storage facility are adequate insulation, ventilation, and heating and the means to enter and remove the tubers efficiently.
A Developmental View of Academic Advising As Teaching

This classic article, upon which many of the subsequent articles reflect, originally appeared in January of 1972 in the Journal of College Student Personnel (volume 13,pp. 12–17) and is reprinted with both permission and deep appreciation. Crookston's article i as based on a paper he presented at a conference on academic advising at Temple Buell College in Denver in July 1970.
In search of Robbins stability

We speculate on whether a certain p-adic stability phenomenon, observed by David Robbins empirically for Dodgson condensation, appears in other nonlinear recurrence relations that ''unexpectedly'' produce integer or nearly-integer sequences. We exhibit an example (number friezes) where this phenomenon provably occurs.
Enantioenriched β-lactone and aldol-type products from regiodivergent carbonylation of racemic cis-epoxides

A new carbonylation catalyst is reported that provides enantioenriched β-lactones and aldol-type products from the carbonylative ring-expansion of racemic cis-epoxides. Detailed analysis of the reaction demonstrates that the epoxide substrates undergo regiodivergent carbonylation reactions instead of traditional kinetic resolutions. This new catalytic system was applied to the synthesis of a key fragment of the antibiotic Globomycin.
Analysis of Fatigue Damage Evolution and Associated Anisotropic Elastic Property Degradation in Random Short-Fiber Composite

A theoretical analysis of cyclic fatigue damage and associated anisotropic property degradation in a random short-fiber composite is presented. The fatigue damage takes various forms of microcracking, originated from microscopic stress concentrators in the highly heterogeneous material system. A probabilistic treatment of the microcracks is in troduced to evaluate the statistical nature of the microscopic fatigue damage. Damage evo lution and accumulation are analyzed through the development of probabilistic density functions of microcrack length and orientation during the cyclic loading history. Consti tutive equations for the damaged fiber composite are then derived on the basis of a self- consistent mechanics scheme in conjunction with a three-dimensional elliptic crack theory and the microcrack density functions. Cyclic fatigue degradation and associated damage- induced anisotropy of composite material properties are determined analytically and checked against experiments. The tensorial nature of mate...
Immunoregulatory Genes and Immunosuppression by Glucocorticoids

Glucocorticoids (GCs) are physiological inhibitors of inflammatory responses and are widely used as immunosuppressive and anti-inflammatory agents. GCs induce (i) lymphocyte apoptosis (Cohen, 1989, Galili, 1983) and (ii) inhibit synthesis of lymphokines (Arya et al., 1984, Culpepper and Lee, 1985, Knudsen et al., 1987, Wang et al., 1993, Zanker et al., 1990) and cell surface molecules (Von Knebel et al., 1990) required for immune function. In spite of the widespread use of GCs, the molecular mechanisms that underlie their therapeutic effects are poorly understood.
Formats for combinatorial synthesis: solid-phase, liquid-phase and surface

Abstract Methods for combinatorial and parallel synthesis continue to evolve in order to meet the demands of modern synthetic organic chemistry. The nature of the support, while typically overlooked, is a key consideration for successful combinatorial organic synthesis. Developments in combinatorial synthesis technologies such as the ‘lab-on-a-chip’ concept and 96-well-plate-compatible resin plugs have been reported, which should contribute to meeting the increasing challenges of this field.
Boosting the accuracy of differentially private histograms through consistency

We show that it is possible to significantly improve the accuracy of a general class of histogram queries while satisfying differential privacy. Our approach carefully chooses a set of queries to evaluate, and then exploits consistency constraints that should hold over the noisy output. In a post-processing phase, we compute the consistent input most likely to have produced the noisy output. The final output is differentially-private and consistent, but in addition, it is often much more accurate. We show, both theoretically and experimentally, that these techniques can be used for estimating the degree sequence of a graph very precisely, and for computing a histogram that can support arbitrary range queries accurately.
Investigating the Near-Infrared Properties of Planetary Nebulae. II. Medium-Resolution Spectra

We present medium-resolution (R approximately 700) near-infrared (lambda = 1 - 2.5 micrometers) spectra of a sample of planetary nebulae (PNe). A narrow slit was used which sampled discrete locations within the nebulae; observations were obtained at one or more positions in the 41 objects included in the survey. The PN spectra fall into one of four general categories: H1 emission line-dominated PNe, H1 and H2 emission line PNe, H2 emission line-dominated PNe, and continuum-dominated PNe. These categories correlate with morphological type, with the elliptical PNe falling into the first group, and the bipolar PNe primarily in the H2 and continuum emission groups. The categories also correlate with C/O ratio, with the O-rich objects falling into the first group and the C-rich objects in the groups. Other spectral features were observed in all catagories, such as continuum emission from the central star, and warm dust continuum emission towards the long wavelength end of the spectra. H2 was detected in four PNe in this survey for the first time. An analysis was performed using the H2 line ratios in all of the PN spectra in the survey where a sufficient number of lines were observed to determine the ortho-to-para ratio and the rotational and vibrational excitation temperatures of the H-2 in those objects. One unexpected result from this analysis is that the H-2 is excited by absorption of ultraviolet photons in most of the PNe, although there are several PNe in which collisional excitation plays an important role. The correlation between bipolar morphology and H2 emission has been strengthened with the new detections of H2 in this survey.
Circumnuclear Dust in Nearby Active and Inactive Galaxies. I. Data

The detailed morphology of the interstellar medium (ISM) in the central kiloparsec of galaxies is controlled by pressure and gravitation. The combination of these forces shapes both circumnuclear star formation and the growth of the central, supermassive black hole. We present visible and near-infrared Hubble Space Telescope images and color maps of 123 nearby galaxies that show the distribution of the cold ISM, as traced by dust, with excellent spatial resolution. These observations reveal that nuclear dust spirals are found in the majority of active and inactive galaxies and they possess a wide range in coherence, symmetry, and pitch angle. We have used this large sample to develop a classification system for circumnuclear dust structures. In spite of the heterogeneous nature of the complete sample, we only find symmetric, two-arm nuclear dust spirals in galaxies with large-scale bars, and these dust lanes clearly connect to dust lanes along the leading edges of the large-scale bars. Not all dust lanes along large-scale bars form two-arm spirals, however, and several instead end in nuclear rings. We find that tightly wound, or low pitch angle, nuclear dust spirals are more common in unbarred galaxies than barred galaxies. Finally, the extended narrow-line region in several of the active galaxies is well resolved. The connection between the ionized gas and circumnuclear dust lanes in four of these galaxies provides additional evidence that a significant fraction of their extended narrow-line region is ambient gas photoionized in situ by the active nucleus. In a future paper we will use our classification system for circumnuclear dust to identify differences between active and inactive galaxies, as well as barred and unbarred galaxies, in well-matched subsamples of these data.
Spectral signatures of gravitationally confined thermonuclear supernova explosions

We consider some of the spectral and polarimetric signatures of the gravitationally confined detonation scenario for Type Ia supernova explosions. In this model, material produced by an off-center deflagration (which itself fails to produce the explosion) forms a metal-rich atmosphere above the white dwarf surface. Using hydrodynamical simulations, we show that this atmosphere is compressed and accelerated during the subsequent interaction with the supernova ejecta. This leads ultimately to the formation of a high-velocity pancake of metal-rich material that is geometrically detached from the bulk of the ejecta. When observed at the epochs near maximum light, this absorbing pancake produces a highly blueshifted and polarized calcium IR triplet absorption feature similar to that observed in several Type Ia supernovae. We discuss the orientation effects present in our model and contrast them to those expected in other supernova explosion models. We propose that a large sample of spectropolarimetric observations can be used to critically evaluate the different theoretical scenarios.
“Synthetic metals”: A novel role for organic polymers

The synthesis and p- and n-doping of polyacetylene, (CH)x, the prototype conducting polymer or “synthetic metal” is described together with a qualitative description of its band structure and changes in band structure on doping to yield positive and negative solitons. Other conducting polymers are briefly discussed. The polyanilines, a large class of versatile conducting polymers involving a novel non-redox doping process, considered as being of significant commercial technological importance are discussed in particular with reference to their ease of processing. Present and future technological uses of conducting polymers are noted.
Defining clinical 'workstation'

Abstract Interest in the physician's workstation has increased, yet often seems to focus on technological issues. At Boston's Beth Israel Hospital, the Center for Clinical Computing includes heavily used clinical workstations. Their evolution over the past 20 years suggests design criteria: the workstation must be patient-centered, the interface must be uniform, and data acquisition must be addressed at a system level. However, it is clinical function that really defines a workstation. The workstation should do the following: display patient information rapidly and flexibly; assist with administrative tasks; facilitate communication; and provide four important types of decision support: access to literature, access to databases, clinical calculation, and ‘synthetic vision,’ or different views of patient data. The solutions to our healthcare problems are not in ‘workboxes’ we can buy, but in creative approaches we can imagine. We need a patient-centered infrastructure and a reduced workload for the clinician-perhaps a ‘worklesstation’.
Vote assignments in weighted voting mechanisms

It is shown that voting can provide the maximum reliability if all nodes have reliability p>or=0.5. Thus, a system designer only needs to consider vote assignments in implementing mutual exclusion mechanisms. Some effective vote assignment algorithms are proposed. Neglecting link failures, it is found that the voting weight for each node can be determined by computing a logarithmic function of local information. Voting operations are formally defined, and an optimization objection function is formulated. A sufficient condition for optimal vote assignment and optimal sets of groups is presented, and it is shown that predefining a set of groups to achieve mutual exclusion is not feasible for a large system. Some algorithms generating optimal or suboptimal assignments for systems with perfect links are proposed. Some variations for systems with imperfect links are discussed, along with some comparisons of the new algorithms against previous algorithms proposed for the problem. >
Flow visualization and motion analysis for a series of four sequential brush seals

Applying the Full Flow Field Tracking (FFFT) method, the flow patterns and the accompanying fluid velocities inside a series of brushes were nonintrusively determined and graphically reconstructed. The visualized flow field revealed regions that are characteristically river-jetting, vortical, and crossflow, and exist upstream, downstream, or within the seal. These flows are especially engendered by variations in fiber void that are spatial and temporal and affect changes in seal leakage and stability. The deformation of the upper half of each of the four sequential brushes as a function of upstream pressure and mass flow was determined. The axial pressure variation across the set of four brushes and the mass flow as a function of the pressure drops are also presented.
Dynamic Monte Carlo simulations for a square-lattice Ising ferromagnet with a phonon heat bath

We derive a direct connection between Monte Carlo time and physical time in terms of physical parameters, using a quantum Hamiltonian with a d-dimensional phonon heat bath interacting with a square-lattice Ising ferromagnet. Based on the calculated transition rates, we perform dynamic Monte Carlo simulations using absorbing Markov chains to measure the lifetimes of the metastable state at low temperatures. We also calculate the lifetimes analytically using absorbing Markov chains. The phonon dynamic gives field-dependent prefactors in the lifetimes at low temperatures, that are different from the piecewise field-independent prefactors obtained from the Glauber dynamic.
The Heating of Thermal Electrons in Fast Collisionless Shocks: The Integral Role of Cosmic Rays

Understanding the heating of electrons to quasi-thermal energies at collisionless shocks has broad implications for plasma astrophysics. It directly impacts the interpretation of X-ray spectra from shocks, is important for understanding how energy is partitioned between the thermal and cosmic-ray populations, and provides insight into the structure of the shock itself. In previous work by Ghavamian et al. we presented observational evidence for an inverse-square relation between the electron-to-proton temperature ratio and the shock speed at the outer blast waves of supernova remnants in partially neutral interstellar gas. There we outlined how lower hybrid waves generated in the cosmic-ray precursor could produce such a relationship by heating the electrons to a common temperature independent of both shock speed and the strength of the ambient magnetic field. Here we explore the mechanism of lower hybrid wave heating of electrons in more detail. Specifically, we examine the growth rate of the lower hybrid waves for both the kinetic (resonant) and reactive cases. We find that only the kinetic case exhibits a growing mode. At low Alfven Mach numbers the growth of lower hybrid waves can be faster than the magnetic field amplification by modified Alfven waves.
Estimation by simulation of monotone dynamical systems

This paper offers a general proof of consistency for the simulated moments estimator in a parameterized family of stochastic models with monotone dynamics. Models with this monotonicity property are frequently encountered in economic applications. The proof of consistency of the estimator draws upon a uniform law of large numbers over a continuum of invariant distributions indexed by the model's parameters.
The Pauli–Lubański vector, complex electrodynamics, and photon helicity

We critically analyze the concept of photon helicity and its connection with the Pauli?Luba?ski vector from the viewpoint of the complex electromagnetic field, sometimes attributed to Riemann but studied by Weber, Silberstein, and Minkowski. To this end, a complex covariant form of Maxwell?s equations is used. Weyl?s two-component wave equation for massless neutrinos is also briefly discussed.
Chiral Anion Phase-Transfer Catalysis Applied to the Direct Enantioselective Fluorinative Dearomatization of Phenols

Chiral anion phase-transfer catalysis has enabled the direct and highly enantioselective fluorinative dearomatization of phenols catalyzed by a BINOL-derived phosphate. The process efficiently transforms simple, readily available phenols into fluorinated chiral small molecules bearing reactive functionality under ambient reaction conditions with high enantioselectivity. The close relationship of the products with well-studied o-quinols provides numerous avenues for synthetic elaboration and exciting opportunities for bioisosteric replacement of hydroxyl with fluorine in natural products.
Passivity of 1018 carbon steel in dimethoxyethane with LiAsF6—observation of electropolymerization

Abstract The passivity and breakdown of passivity of 1018 carbon steel in dimethoxyethane with 0.5 M LiAsF6 was studied by electrochemical and surface analytical techniques. Carbon steel exhibits passivity over a large anodic potential range. Several different passivation mechanisms, including solvent adsorption, operate in this potential domain. In addition, another passivation mechanism involving electropolymerization of the solvent and complexation the LiAsF6 was observed. A polymer film did not form in supporting electrolytes other than LiAsF6. The effects of small amounts of water on the extent of the passive region and the possibility of polymer growth are discussed.
Plancherel–Rotach asymptotics of second-order difference equations with linear coefficients

Abstract In this paper, we provide a complete Plancherel–Rotach asymptotic analysis of polynomials that satisfy a second-order difference equation with linear coefficients. According to the signs of the parameters, we classify the difference equations into six cases and derive explicit asymptotic formulas of the polynomials in the outer and oscillatory regions, respectively. It is remarkable that the zero distributions of the polynomials may locate on the imaginary line or even on a sideways Y-shape curve in some cases. Finally, we apply our results to find asymptotic formulas for associated Hermite and associated Charlier polynomials.
Interactions between solar neutrinos and solar magnetic fields

Abstract We attempt to correlate all of the available solar-neutrino data with the strong magnetic fields these neutrinos encounter in the solar interior along their Earth-bound path. We approximate these fields using the photospheric, magnetograph-measured flux from central latitude bands, time delayed to proxy the magnetic fields in the solar interior. Our strongest evidence for anticorrelation is for magnetic fields within the central ±5° solar-latitude band that have been delayed by 0.85 ± 0.55 yr. Assuming a neutrino-magnetic interaction, this might indicate that interior fields travel to the solar surface in this period of time. As more solar-neutrino flux information is gathered, the question of whether this result arises from a physical process or is merely a statistical fluke should be resolved, providing that new data are obtained spanning additional solar cycles and that correlation studies focus on these same regions of the solar magnetic field.
Leading Charm in Hadron-Nucleus Interactions in the Intrinsic Charm Model

Leading charm hadrons produced in hadron-nucleus interactions cannot be adequately described within the parton fusion model. Recent results on charm baryon production in Sigma{sup -} A interactions at 330 GeV with the WA89 detector disagree with fusion predictions. Intrinsic heavy quark pairs in the Sigma{sup -}(dds) wave function provide a simple mechanism for producing fast charm hadrons. We calculate leading charm baryon production from Sigma{sup -}, pi{sup -} and p projectiles in a two component model combining partonfusion with intrinsic charm. Final state D{sup -}, Sigma{sub c}{sup 0}, Xi{sub c}{sup +}, and Lambda{sub c}{sup +} d sigma/dx{sub F} distributions and D{sup -}/D{sup +}, D{sub s}{sup -}/D{sub s}{sup +} and Lambda{sub c}{sup +}/overline Lambda{sub c}{sup +} asymmetries are compared to WA89 data. Predictions are made for 650 GeV Sigma{sup -} A and pi{sup -} A interactions in the SELEX detector at Fermilab and for 800 GeV pA interactions.
Short-term effects of breast cancer on labor market attachment: results from a longitudinal study

In this longitudinal study, we examine the consequences of breast cancer for women's labor market attachment for the 6-month period following diagnosis. Women with breast cancer, with the exception of those having in situ cancer, were less likely to work 6 months following diagnosis relative to a control sample of women drawn from the Current Population Survey. Breast cancer's non-employment effect appears to be twice as large for African-American women. Women with breast cancer who remained working worked fewer hours than women in the control group.
Magnetite and magnetotaxis in microorganisms

Magnetotactic bacteria from freshwater and marine sediments orient and navigate along geomagnetic field lines. Their magnetotactic response is based on intracellular, single magnetic domains of ferrimagnetic magnetite, which impart a permanent magnetic dipole moment to the cell.
When, Why, and How Controversy Causes Conversation

How does controversy affect conversation? Five studies using both field and laboratory data address this question. Contrary to popular belief, controversial things are not necessarily more likely to be discussed. Controversy increases likelihood of discussion at low levels, but beyond a moderate level of controversy, additional controversy actually decreases likelihood of discussion. The controversy-conversation relationship is driven by two countervailing processes. Controversy increases interest (which increases likelihood of discussion) but simultaneously increases discomfort (which decreases likelihood of discussion). Contextual factors such as anonymity and whether people are talking to friends or strangers moderate the controversy-conversation relationship by impacting these component processes. Our framework sheds light on how, when, and why controversy affects whether or not things are discussed.
An unusual rearrangement of N-substituted thiophosphoryl carbonyl mixed imides

Abstract N-Substituted O,O-dimethyl N-benzoyl phosphoramidothioates ( III , R = Me, Ph but not H) undergo an uncatalyzed unimolecular rearrangement in an inert solvent; whereby, the carbonyl oxygen atom exchanges position with the thiophosphoryl sulfur atom (an O,S Switch) and forms O,O-dimethyl N-thiobenzoyl phosphoramidates ( IV , R = Me, Ph).
Static and dynamic Monte Carlo simulations of BR electrodeposition on Ag(100)

Abstract We study the static and dynamic properties of bromine electrosorption onto single-crystal silver (1 0 0) electrodes by Monte Carlo (MC) simulation. At room temperature the system displays a second-order phase transition between a low-coverage disordered phase at more negative electrode potentials and a c(2×2) ordered phase with bromine coverage 1/2 at more positive potentials. We explore the phase diagram and demonstrate that the broad shoulder observed in room-temperature cyclic voltammograms is due to local fluctuations resembling ordered phases with coverage 1/4, which exist in the model at much lower temperatures. We construct a dynamic MC algorithm using a thermally activated stochastic barrier-hopping model for the microscopic dynamics. We use this algorithm to study the phase ordering and disordering processes following sudden potential steps between the disordered phase and the c(2×2) phase, and to study the sweep-rate dependence in simulated cyclic-voltammetry experiments.
Gonioheptolides A and B: Novel eight-membered-ring lactones from Goniothalamus giganteus (Annonaceae)

Two novel eight-membered-ring lactones, gonioheptolides A (1 and B (3), have been isolated from the bark of Goniothalamus giganteus. The structures were elucidated by IR, MS, 1H and 13C NMR, COSY, HMQC, HMBC, and NOESY spectra. 1 and 3 showed marginal cytotoxicities to certain human solid tumor cells in culture. A biogenetic pathway of the 14 styryllactones found in G. giganteus is proposed.
QCD modeling of hadron physics

We review recent developments in the understanding of meson properties as solutions of the Bethe–Salpeter equation in rainbow-ladder truncation. Included are recent results for the pseudoscalar and vector meson masses and leptonic decay constants, ranging from pions up to c c ¯ bound states; extrapolation to b b ¯ states is explored. We also present a new and improved calculation of F π ( Q 2 ) and an analysis of the πγγ transition form factor for both π ( 140 ) and π ( 1330 ) . Lattice-QCD results for propagators and the quark-gluon vertex are analysed, and the effects of quark-gluon vertex dressing and the three-gluon coupling upon meson masses are considered.
Production of Olefins by Oxidative Dehydrogenation of Propane and Butane over Monoliths at Short Contact Times

The autothermal production of olefins from propane or n-butane by oxidative dehydrogenation and cracking in air or oxygen at atmospheric pressure over noble metal coated ceramic foam monoliths at contact times of {approximately}5 milliseconds has been studied. On Pt, synthesis gas (CO and H{sub 2}) dominates near its stoichiometry, while olefin production dominates at higher fuel-to-oxygen ratios. No carbon buildup is observed, and catalysts exhibit no deactivation over at least several days. On Rh, primarily synthesis gas is produced under these conditions, while on Pd, carbon deposition rapidly deactivates the catalyst. The authors observed up to 65% selectivity to olefins at nearly 100% conversion of propane or n-butane with a catalyst contact time of 5 ms. Ethylene selectivity is maximized by increasing the reaction temperature, either by preheating the reactants or by using oxygen enriched air. Propylene selectivity is maximized by lower temperature and shorter catalyst contact time. Very small amounts alkanes and higher molecular weight species are obtained, suggesting that a homogeneous pyrolysis mechanism is not occurring. A very simple reaction mechanism appears to explain the observed product distribution. Reactions are initiated by oxidative dehydrogenation of the alkane by adsorbed oxygen to form a surface alkyl. On Pt, {beta}-hydrogenmore » and {beta}-alkyl elimination reactions of adsorbed alkyl dominate which lead to olefin production rather than cracking to C{sub s} and H{sub s}. 24 refs., 14 figs., 4 tabs.« less
Monitoring magnetohydrodynamics boundary layers using emission line shape features

A strong correlation has been found between the center dip slope of self-reversed atomic potassium emission lines in a coal-fired magnetohydrodynamics flow and the thickness of the cool boundary layer surrounding the hot core flow. The boundary-layer profile was determined indirectly from line shape fitting of simultaneous time-resolved multiwavelength emission and absorption spectra. For line shape fitting, a power law model with an effective boundary-layer width is proposed for modeling the radiative transfer across a turbulent boundary layer, rather than an inverse power law model that is used for a turbulent velocity boundary layer. A simple relationship can be written between the center dip slope and the effective boundary layer width that will allow real-time monitoring of the turbulent flow.
KNOW THE STAR, KNOW THE PLANET. II. SPECKLE INTERFEROMETRY OF EXOPLANET HOST STARS

A study of the host stars to exoplanets is important for understanding their environment. To that end, we report new speckle observations of a sample of exoplanet host primaries. The bright exoplanet host HD 8673 (= HIP 6702) is revealed to have a companion, although at this time we cannot definitively establish the companion as physical or optical. The observing lists for planet searches and for these observations have for the most part been pre-screened for known duplicity, so the detected binary fraction is lower than what would otherwise be expected. Therefore, a large number of double stars were observed contemporaneously for verification and quality control purposes, to ensure that the lack of detection of companions for exoplanet hosts was valid. In these additional observations, 10 pairs are resolved for the first time and 60 pairs are confirmed. These observations were obtained with the USNO speckle camera on the NOAO 4 m telescopes at both KPNO and CTIO from 2001 to 2010.