cssi/SciSciGPT-SciSciNet huggingface dataset:
Habit formation: implications for alcoholism research.

Characteristics of individuals with severe alcohol use disorders include heightened cue sensitivity, compulsive seeking, craving, and continued alcohol use in the face of negative consequences. Animal models are useful for understanding behavioral and neurological mechanisms underlying problematic alcohol use. Seeking of operant reinforcers including alcohol is processed by two mechanisms, commonly referred to as “goal-directed” (action-outcome) and “habitual” (stimulus-response). As substance use disorders are characterized by continued use regardless of unfavorable outcomes, it is plausible that drug use causes an unnatural disruption of these mechanisms. We present a critical analysis of literature pertaining to behavioral neuroscience alcoholism research involving habit formation. Traditionally, when operant behavior is unaffected by a loss of subjective value of a reinforcer (devaluation), the behavior is considered habitual. Acquisition of instrumental behavior requires corticostriatal mechanisms that depend heavily on the prefrontal cortex and ventral striatum, whereas practiced behavior is more predominantly controlled by the dorsal striatum. Dopaminergic signaling is necessary for the neurological adaptations involved in stimulus-response action, and drugs of abuse appear to facilitate habitual behavior through high levels of dopamine release. Evidence suggests that the use of alcohol as a reinforcer expedites habit formation, and that a history of alcohol use produces alterations in striatal morphology, aids habit learning for non-psychoactive reinforcers, and promotes alcohol drinking despite aversive adulterants. In this review, we suggest directions for future alcoholism research that seeks to measure action made despite a devalued outcome, including procedural modifications and genotypic, pharmacological, or neurological manipulations. Most alcoholism models currently in use fail to reach substantial blood ethanol concentrations, a shortcoming that may be alleviated through the use of high-drinking rodent lines. Additionally, satiety, one common mechanism of devaluing reinforcers, is not recommended for alcohol research because the psychoactive effects of alcohol depress response rates, mimicking devaluation effects. Overall, further research of habit formation and potentially related perseverative behaviors could be invaluable in discovering genetic variance, traits that correlate with persistent alcohol seeking, implicated neural structures and processes of alcohol use, and eventually novel pharmacological treatment for alcoholism.
Effects of Support Material and Sulfation on Propane Oxidation Activity over Platinum

Abstract Propane oxidation is used as a model reaction to study effects of platinum concentration, support material, and catalyst sulfation. Support materials examined are γ-alumina, zirconia, and silica in a platinum dispersion range from about 0.05 to 1.0. Experiments are conducted with recirculation batch and integral flow reactors. For highly dispersed platinum, the activity decreases in the order zirconia > silica > γ-alumina. Over larger platinum particles, the batch experiments show the same turnover rate on the three supports. On highly dispersed platinum, sulfation, via SO 2 oxidation or H 2 SO 4 exposure, significantly increases the catalytic activity of Pt/γ-alumina, while Pt/silica and Pt/zirconia remain unaffected. Surface acid strength is measured with Hammett indicators. Upon sulfation, the acid strength of zirconia and γ-alumina increases, while no change is observed for silica. Acid strength does not have a major influence on propane-oxidation activity. Within the experimental error, the apparent activation energy for propane oxidation is independent of metal concentration, support material, and sulfation, suggesting that changes in activity are primarily the result of a change in reaction-site density.
De-differentiation confers multidrug resistance via noncanonical PERK-Nrf2 signaling.

Malignant carcinomas that recur following therapy are typically de-differentiated and multidrug resistant (MDR). De-differentiated cancer cells acquire MDR by up-regulating reactive oxygen species (ROS)–scavenging enzymes and drug efflux pumps, but how these genes are up-regulated in response to de-differentiation is not known. Here, we examine this question by using global transcriptional profiling to identify ROS-induced genes that are already up-regulated in de-differentiated cells, even in the absence of oxidative damage. Using this approach, we found that the Nrf2 transcription factor, which is the master regulator of cellular responses to oxidative stress, is preactivated in de-differentiated cells. In de-differentiated cells, Nrf2 is not activated by oxidation but rather through a noncanonical mechanism involving its phosphorylation by the ER membrane kinase PERK. In contrast, differentiated cells require oxidative damage to activate Nrf2. Constitutive PERK-Nrf2 signaling protects de-differentiated cells from chemotherapy by reducing ROS levels and increasing drug efflux. These findings are validated in therapy-resistant basal breast cancer cell lines and animal models, where inhibition of the PERK-Nrf2 signaling axis reversed the MDR of de-differentiated cancer cells. Additionally, analysis of patient tumor datasets showed that a PERK pathway signature correlates strongly with chemotherapy resistance, tumor grade, and overall survival. Collectively, these results indicate that de-differentiated cells up-regulate MDR genes via PERK-Nrf2 signaling and suggest that targeting this pathway could sensitize drug-resistant cells to chemotherapy.
Silica-supported tantalum clusters: catalyst for alkane conversion.

Silica-supported tantalum clusters (on average, approximately tritantalum) were formed by the treatment, in either H2 or ethane, of adsorbed Ta(CH2Ph)5; the supported catalyst is active for ethane conversion to methane and propane at 523 K, with the used catalyst containing clusters of the same average nuclearity as the precursor.
Building a new kind of graded-Z shield for Swift's burst alert telescope

The Burst Alert Telescope (BAT) on Swift has a graded-Z Shield that closes out the volume between the coded aperture mask and the Cadmium-Zinc-Telluride (CZT) detector array. The purpose of the 37-kilogram shield is to attenuate gamma rays that have not penetrated the coded aperture mask of the BAT instrument and are therefore a major source of noise on the detector array. Unlike previous shields made from plates and panels, this shield consists of multiple layers of thin metal foils (lead, tantalum, tin, and copper) that are stitched together much like standard multi-layer insulation blankets. The shield sections are fastened around BAT, forming a curtain around the instrument aperture. Strength tests were performed to validate and improve the design, and the shield will be vibration tested along with BAT in late 2002. Practical aspects such as the layup design, methods of manufacture, and testing of this new kind of graded-Z Shield are presented.
Side moment exerted by a two-component liquid payload on a spinning projectile

Abstract : A linear boundary layer theory is derived for two liquids in a cylindrical cavity in a coning and spinning projectile. Predicted eigenfrequencies agree well with available experimental results. Side moment coefficients are computed for various cases. It is shown that significant increases in the single-liquid side moment can be caused by the addition of a small amount of heavier liquid and for certain locations of the liquid interface, pairs of eigenfrequencies can coalesce.
Partition function zeroes of a self-dual Ising model

Abstract We consider the Ising model on an M × N rectangular lattice with an asymmetric self-dual boundary condition, and derive a closed-form expression for its partition function. We show that zeroes of the partition function are given by the roots of a polynomial equation of degree 2M−1, which trace out certain loci in the complex temperature plane. Particularly, it is shown that (a) real solutions of the polynomial equations always lead to zeroes on the unit circle and a segment of the negative real axis, and (b) all temperature zeroes lie on two circles in the limit of M → ∞ for any N. Closed-form expressions of the loci as well as the density of zero distributions in the limit of N → ∞ are derived for M = 1 and 2. In addition, we explain the reason of, and establish the criterion for, partition function zeroes of any self-dual spin model to reside precisely on the unit circle. This elucidates a recent finding in the case of the self-dual Potts model.
AN EXPERIMENTAL INVESTIGATION OF VIBRATION LOCALIZATION IN DISORDERED MULTI-SPAN BEAMS

Abstract The results of an experimental investigation of the effects of span length disorder on the dynamics of mono-coupled, multi-span beams are reported. Two experimental specimens are considered: a nominally periodic 12-span beam with equal spacing between simple supports, and the corresponding disordered beam which features randomly spaced supports. Experimental results demonstrate that the transmission of vibration which takes place within the frequency passbands of the periodic beam is greatly hindered when span length randomness is introduced. The spatial localization of both the mode shapes and the steady state harmonic response to an end excitation is observed in the disordered 12-span beam, especially for frequencies which lie within the second passband. Very good quantitative agreement is obtained between experimental results and theoretical findings for both ordered and disordered configurations. Furthermore, an experimental estimation of the localization factory yields satisfactory agreement with the theoretical result for an infinite multi-span beam. This work reports one of the first systematic experiments carried out to demonstrate the occurrence of vibration localization in nearly periodic structures.
Highly Enantioselective Epoxidation of α,β-Unsaturated Esters by Chiral Dioxirane

This paper describes a highly enantioselective epoxidation of α,β-unsaturated esters using the fructose-derived ketone 2 as catalyst and Oxone as oxidant. High ee's have been obtained for a number of trans and trisubstituted substrates (82−98% ee). The results described show that it is feasible for dioxiranes to effectively epoxidize electron-deficient olefins with high ee's.
Strong stability of internal system descriptions

This article introduces a new notion of stability for internal autonomous system descriptions that is referred to as ‘strong stability’ and characterises the case of avoiding overshoots for all initial conditions within a given sphere. This is a stronger notion of stability compared with alternative definitions (asymptotic, Lyapunov), which allows the analysis and design of control systems described by natural coordinates to have no overshooting response for arbitrary initial conditions. For the case of linear time-invariant systems necessary and sufficient conditions for strong stability are established in terms of the negative definiteness of the symmetric part of the state matrix. The invariance of strong stability under orthogonal transformations is established and this enables the characterisation of the property in terms of the invariants of the Schur form of the state matrix. Some interesting relations between strong stability and special forms of coordinate frames are examined and links between th...
Cromolyn sodium does not inhibit hypoxic pulmonary vasoconstriction in sheep.

Cromolyn sodium has been reported to inhibit hypoxic pulmonary vasoconstriction (HPV) in dogs and sheep, presumably by stabilizing mast cell membranes and thereby preventing the release of mediators such as leukotrienes. Because the effects of leukotriene synthesis and receptor blockers on HPV have been variable across studies, we studied the effect of cromolyn on HPV in the halothane-anesthetized sheep, a model in which we have found leukotriene synthesis and receptor blockers to be ineffective. In control animals, hypoxia (FIO2 = 0.13) increased pulmonary artery pressure (Ppa) 67% and pulmonary vascular resistance 85%, and these responses were reproducible with a second episode of hypoxia. In a second group of sheep, hypoxia (FIO2 = 0.13) during cromolyn administration (6 mg.kg-1.min-1) for 30 min increased (Ppa) 104% and increased pulmonary vascular resistance 124%. In a third group of sheep, cromolyn sodium (6 mg.kg-1.min-1) without hypoxia did not significantly affect pulmonary hemodynamics. We conclude that cromolyn sodium does not inhibit HPV in halothane-anesthetized sheep. In experimental designs in which cromolyn does alter HPV, the effect is more likely due to altered release of modulators of HPV rather than to decreased release of obligatory mediator of HPV.
Relaxation of mass-gaining stars

The study of relaxing low-mass stars, after gaining mass, to their corresponding main-sequence counterparts is presented. An initial mass of the star was 0.56 M⊙ which was gaining mass at a rate increasing gradually from about 10-10 to about 10-8 M⊙y-1. The initial chemical composition used for computation was: 75% H, 22.3% He, and 2.7% heavy elements. The mass-gaining stellar model is assumed to be spherically symmetric and in hydrostatic and thermal equilibrium; also it is assumed that mass is absorbed through the stellar envelope from a uniformly distributed outer shell. A sequence of static models was calculated with time steps between the models chosen in such a way as to maintain the changes in physical variables with certain limits from one model to the next. This series of mass-gaining calculations was carried out to the model of 0.835 M⊙. Another series of calculations was carried out in order to investigate the effects of stopping the mass transfer and allowing the star to relax. Each of the twelve selected mass-gaining models was used as the starting point for one of these relaxation sequences; and for each of these twelve masses, a zero-age main sequence model was calculated. The relaxation models were calculated from the same evolutionary technique except that the mass-transfer rate was set to zero. The criterion for stopping these relaxation runs was that the gravitational luminosity term in the envelope should have returned to the main sequence value.
Neighbors and the evolution of the comparative advantage of nations: Evidence of international knowledge diffusion?

Abstract The literature on knowledge diffusion shows that knowledge decays strongly with distance. In this paper we document that the probability that a product is added to a country's export basket is, on average, 65% larger if a neighboring country is a successful exporter of that same product. For existing products, growth of exports in a country is 1.5% higher per annum if it has a neighbor with comparative advantage in these products. While these results could be driven by a common third factor that escapes our controls, they align with our expectations of the localized character of knowledge diffusion.
Analytic expressions for mean magnification by a quadrupole gravitational lens

We derive an analytic expression for the mean magnification due to strong gravitational lensing, using a simple lens model: a singular isothermal sphere embedded in an external shear field. We compute separate expressions for two-image and four-image lensing. For four-image lensing, the mean magnification takes a particularly simple form: μ4 = 3.6/ , where γ is the external shear. We compare our analytic results with a numerical evaluation of the full magnification distribution. The results can be used to understand the magnification bias that favors the discovery of four-image systems over two-image systems in flux-limited lens surveys.
A Mechanics Approach to Static Friction of Elastic–Plastic Fractal Surfaces

A contact mechanics theory of static friction is presented for isotropic rough surfaces exhibiting fractal behavior. The analysis is based on a piecewise power-law size distribution and a normal slope distribution of the asperity contacts and elastic-fully plastic deformation models. Numerical integration yields solutions for the normal and friction forces in terms of fractal parameters, elastic-plastic material properties, and interfacial shear strength. The variation of the static coefficient of friction with normal load is related to the effect of the surface topography on the dominant deformation mode at the asperity contacts. Plastic deformation of the smaller asperity contacts dominates at low loads and elastic deformation of the larger asperity contacts dominates at high loads. The critical load signifying the transition from predominantly plastic to elastic deformation depends on the fractal parameters and material properties. In the low-load range, the static coefficient of friction decreases with the increase of the load, while in the high-load range it increases with the load. Numerical results for copper fractal surfaces illustrate the effects of normal load, surface topography, and interfacial shear strength on the static coefficient of friction.
Stable Oxypyridinium Triflate (OPT) Salts for the Synthesis of Halobenzyl Ethers

Abstract A collection of new oxypyridinium triflate reagents (1a–d) for the synthesis of halobenzyl ethers from alcohols under “mix‐and‐heat” conditions is described. The reagents are stable organic salts that can be stored indefinitely and handled without special precautions, making them attractive for general use in organic synthesis. Halobenzylation of representative alcohols occurs in good to excellent yield. This paper is dedicated to Professor Ken Goldsby (FSU) for his promotion and support of undergraduate research.
Selectivity in Nickel-Catalyzed Rearrangements of Cyclopropylen-ynes

The Ni/NHC-catalyzed rearrangement of cyclopropylen-ynes is described. Two different heterocycles, cyclopentane- or cycloheptene-based, were obtained. However, by employing ItBu as the NHC ligand, cyclopentane products were obtained selectively under mild conditions.
Reversible QRS changes during acute myocardial ischemia

Reversible QRS complex changes associated with ST-segment shift during acute myocardial ischemia (AMI) have been reported sporadically in isolated cases or in small patient groups but have not been analyzed systematically in a sizable cohort of patients. During the past 4 years, a purposeful search was made for electrocardiograms with documented reversible QRS changes associated with all acute injury pattern. The measured variables included distribution of leads with ST-segment deviation and reciprocal ST-segment depression, magnitude of the ST-segment shift, amplitude and direction of the initial and terminal QRS deflections, QRS duration, QTc duration, and U wave amplitude. Reversible QRS changes encountered in 29 patients with AMI included new Q waves (n = 3), decreased Q amplitude (n = 2), QS change to qRS or qR (n = 6), disappearance of QS or Q (n = 4), increased R amplitude (n = 9), decreased R amplitude (n = 6), increased S amplitude by more than 75% (n = 18), and increased QRS duration (n = 4). Changes in the initial configuration were present in 24 of the 29 patients. Reversible changes of the terminal QRS portion occurred in all 29 patients, and reversible changes of the initial QRS portion occurred in 23 (79%), whereas QRS duration increased in 4 patients. Reversible QRS changes during AMI are attributed to passive pull by the ST-segment shift and intraventricular conduction disturbance.
Eulerian quasisymmetric functions for the type B Coxeter group and other wreath product groups

Eulerian quasisymmetric functions were introduced by Shareshian and Wachs in order to obtain a q-analog of [email protected]?s exponential generating function formula for the Eulerian numbers (Shareshian and Wachs, 2010 [17]). They are defined via the symmetric group, and applying the stable and nonstable principal specializations yields formulas for joint distributions of permutation statistics. We consider the wreath product of the cyclic group with the symmetric group, also known as the group of colored permutations. We use this group to introduce colored Eulerian quasisymmetric functions, which are a generalization of Eulerian quasisymmetric functions. We derive a formula for the generating function of these colored Eulerian quasisymmetric functions, which reduces to a formula of Shareshian and Wachs for the Eulerian quasisymmetric functions. We show that applying the stable and nonstable principal specializations yields formulas for joint distributions of colored permutation statistics, which generalize the Shareshian-Wachs q-analog of [email protected]?s formula, formulas of Foata and Han, and a formula of Chow and Gessel.
The value of international cooperation for abating global climate change

Abstract Because abatement of global climate change is a public good, independent national actions may not produce the efficient quantity. Using a numerical integrated-assessment model, abatement costs and damages induced by climate change are compared at the cooperative and noncooperative solutions to a set of two-party dynamic games between the industrialized and developing countries. Games with perfect and imperfect information about climate and economic factors are considered. Across 144 games with perfect information, incorporating different values of climate and economic parameters, the noncooperative solution usually yields global benefits comparable to those of the cooperative solution. In about one-fifth of these games, however, a second noncooperative solution exists which yields none of the benefits of the cooperative solution. In a game with imperfect information, where the state of nature is uncertain in the first but known in the second of two periods, the expected benefits of the noncooperative solution are 98% of the expected benefits of the cooperative solution. In contrast to single-agent studies which show little cost to delaying abatement, the benefits of cooperation are usually lost if cooperation is delayed 20 years.
Dynamical Expansion of H II Regions from Ultracompact to Compact Sizes in Turbulent, Self-gravitating Molecular Clouds

The nature of ultracompact H II regions (UCHRs) remains poorly determined. In particular, they are about an order of magnitude more common than would be expected if they formed around young massive stars and lasted for one dynamical time, around 104 yr. We here perform three-dimensional numerical simulations of the expansion of an H II region into self-gravitating, radiatively cooled gas, both with and without supersonic turbulent flows. In the nonturbulent case, we find that H II region expansion in a collapsing core produces nearly spherical shells, even if the ionizing source is off-center in the core. This agrees with analytic models of blast waves in power-law media. In the turbulent case, we find that the H II region does not disrupt the central collapsing region, but rather sweeps up a shell of gas in which further collapse occurs. Although this does not constitute triggering, as the swept-up gas would eventually have collapsed anyway, it does expose the collapsing regions to ionizing radiation. These objects can have radio flux densities consistent with unresolved UCHRs. We suggest that these objects, which will not all themselves form massive stars, may form the bulk of observed UCHRs. As the larger shell will take over 105 yr to complete its evolution, this could solve the timescale problem. Our suggestion is supported by the ubiquitous observation of more diffuse emission from compact H II regions surrounding UCHRs.
The Dark Side of the Online Self: A Pragmatist Critique of the Growing Plague of Revenge Porn

This study seeks to understand and critique the growing online trend of “revenge porn,” or the intentional embarrassment of identifiable individuals through the posting of nude images online. This posting of intimate pictures, often done out of motives of revenge for perceived relational scorn, is enhanced by the varying levels of online anonymity. Using the theoretical framework of John Dewey's pragmatism, this study both analyzes this understudied but complex new problem precipitated by the conditions of the online self and establishes the groundwork for the use of pragmatist ethics in other areas of communication ethics.
New entrant and closure provisions : how do they distort?

Provisions to endow new entrants with free allowances and to require closed facilities to forfeit allowance endowments are ubiquitous in the EU Emissions Trading Scheme, but a new design feature in cap-and-trade systems. This essay seeks to explore, within a comparative statics framework, the effect of these provisions on agent behavior in output and emissions markets assuming profit maximization. The main conclusion is that the principal effect is on capacity. The effect of the resulting over-capacity on output markets is to reduce output price and to increase output. The effect on emissions markets is more ambiguous in that it depends on the emission characteristics of the new capacity, existing capacity, and the capacity not retired, and the distribution of the excess capacity among these categories.
Surface science investigations of oxidative chemistry on gold.

Because of gold's resistance to oxidation and corrosion, historically chemists have considered this metal inert. However, decades ago, researchers discovered that highly dispersed gold particles on metal oxides are highly chemically active, particularly in low-temperature CO oxidations. These seminal findings spurred considerable interest in investigations and applications of gold-based materials. Since the discovery of gold's chemical activity at the nanoscale, researchers found that bulk gold also has interesting catalytic properties. Thus, it is important to understand and contrast the intrinsic chemical properties of bulk gold with those of nanoparticle Au. Despite numerous studies, the structure and active site of supported Au nanoclusters and the active oxygen species remain elusive, and model studies under well-controlled conditions could help identify these species. The {111} facet has the lowest surface energy and is the most stable and prevalent configuration of most supported gold nanoparticles. Therefore, a molecular-level understanding of the physical properties and surface chemistry of Au(111) could provide mechanistic details regarding the nature of Au-based catalysts and lead to improved catalytic processes. This Account focuses on our current understanding of oxidative chemistry on well-defined gold single crystals, predominantly from recent investigations on Au(111) that we have performed using modern surface science techniques. Our model system strategy allows us to control reaction conditions, which assists in the identification of reaction intermediates, the determination of the elementary reaction steps, and the evaluation of reaction energetics for rate-limiting steps. We have employed temperature-programmed desorption (TPD), molecular beam reactive scattering (MBRS), and Auger electron spectroscopy (AES) to evaluate surface oxidative chemistry. In some cases, we have combined these results with density functional theory (DFT) calculations. By controlling the reaction parameters that determine product selectivity, we have examined the chemical properties of bulk gold. Based on our investigations, the surface-bound oxygen atoms are metastable at low temperature. We also demonstrate that the oxygen atoms and formed hydroxyls are responsible for some of the distinct chemical behavior of gold and participate in surface reactions either as a Bronsted base or a nucleophilic base. We observe similar reaction patterns on gold surfaces to those on copper and silver surfaces, suggesting that the acid-base reactions that have been observed on copper and silver may also occur on gold. Our model chemical studies on gold surfaces have provided intrinsic fundamental insights into high surface area gold-based catalysts and the origin of the reactive oxygen species.
Palladium-Catalyzed Chemoselective Monoarylation of Hydrazides for the Synthesis of [1,2,4]Triazolo[4,3-a]pyridines

An efficient and convenient method for the synthesis of [1,2,4]triazolo[4,3-a]pyridines was exemplified by the synthesis of 20 analogues bearing a variety of substituents at the 3-position. The methodology involves a palladium-catalyzed addition of hydrazides to 2-chloropyridine, which occurs chemoselectively at the terminal nitrogen atom of the hydrazide, followed by dehydration in acetic acid under microwave irradiation.
Are polychaetes sources of habitat heterogeneity for harpacticoid copepods in the deep sea

Abstract Jumars' grain-matching model of community organization in the deep sea states that individual benthic organisms create habitat heterogeneity exploited by other species. We tested this hypothesis using material collected from 1050 m depth in San Diego Trough (32°52.4′N, 117°45.5′W). Polychaetes were investigated as potential creators of habitat heterogeneity; harpacticoid copepods were tested as responding species. We combined the polychaete species into functional groups based on feeding mode and mobility and tested for significant positive correlations between the harpacticoid species and the polychaete functional groups. Significantly more significant positive correlations were found than expected by chance, supporting the grain-matching hypothesis. We rejected an alternative hypothesis that the correlations reflected a common response by both polychaetes and harpacticoids to an external process.
Two-photon processes for particle production at high energies

The literature of the past three years on the two-photon process for particle production e± + e– → e± + γ* + e– + γ* → e± + e– + X (where X is any C = + state) or p + p → X1 + γ* + X2 + γ* → X1 + X2 + µ+ + µ– (where X1, X2 are hadron states) is reviewed in some detail. Both the theoretical aspects and the experimental feasibility of various processes are discussed especially for experimentalists' convenience.
Global regularity of 3D rotating Navier-Stokes equations for resonant domains

Abstract We prove existence on infinite time intervals of regular solutions to the 3D rotating Navier-Stokes equations in the limit of strong rotation (large Coriolis parameter Ω). This uniform existence is proven for periodic or stress-free boundary conditions for all domain aspect ratios, including the case of three wave resonances which yield nonlinear “ 21 2 - dimensional ” limit equations; smoothness assumptions are the same as for local existence theorems. The global existence is proven using techniques of the Littlewood-Paley dyadic decomposition. Infinite time regularity for solutions of the 3D rotating Navier-Stokes equations is obtained by bootstrapping from global regularity of the limit equations and convergence theorems.
Synthesis and characterization of unsymmetrical squaraines: a new class of cyanine dyes

Abstract A new class of unsymmetrical cyanine dyes and their precursors has been synthesized and characterized with the aid of 1H-NMR, IR- and mass spectroscopy. The dyes exhibit high melting points, poor solubility in organic solvents and absorption maxima in the range 640–670 nm with high extinction coefficients.
Pulsar X-Ray and Gamma-Ray Pulse Profiles: Constraint on Obliquity and Observer Angles

We model the thermal X-ray profiles of Geminga, Vela, and PSR 0656+14, which have also been detected as γ-ray pulsars, to constrain the phase space of obliquity and observer angles required to reproduce the observed X-ray pulsed fractions and pulse widths. These geometrical constraints derived from the X-ray light curves are explored for various assumptions about surface temperature distribution and flux anisotropy caused by the magnetized atmosphere. We include curved spacetime effects on photon trajectories and the magnetic field. The observed γ-ray pulse profiles are double peaked with phase separations of 0.4-0.5 between the peaks. Assuming that the γ-ray profiles are due to emission in a hollow cone centered on the magnetic pole, we derive the constraints on the phase space of obliquity and observer angles, for different γ-ray beam sizes, required to produce the observed γ-ray peak phase separations. We compare the constraints from the X-ray emission to those derived from the observed γ-ray pulse profiles and find that the overlapping phase space requires both obliquity and observer angles to be smaller than 20°-30°, implying γ-ray beam opening angles of at most 30°-35°.
Measuring Preferences for Really New Products.

Abstract The goal of this research is to improve preference measurement for really new products. An initial assumption validated in the first study is that consumers have greater uncertainty when estimating the usefulness of really new products than they have with incremental new products. Consumers cope with this uncertainty by using certain inferential techniques that are not well captured by standard preference measurement techniques, such as conjoint. This research examines techniques for incorporating both mental simulation and analogies into an existing preference measurement technique and shows that some methods enhance and other methods hinder predictive accuracy.
Immersive Simulation of Visual Impairments Using a Wearable See-through Display

Simulation of a visual impairment may lead to a better understanding of how individuals with visual impairments perceive the world around them and could be a useful design tool for interface designers to identify accessibility barriers. Current simulation tools, however, suffer from a number of limitations, pertaining cost, accuracy and immersion. We present a simulation tool (SIMVIZ) that mounts a wide angle camera on a head-mounted display to create a see-through stereoscopic display that simulates various types and levels of visual impairments. A qualitative user study evaluates the immersiveness, usability and effectiveness of SIMVIZ versus using a smartphone based simulator. SIMVIZ enables quick accessibility inspections during iterative software development.
The preparation of N-carboalkoxypyrazoles and N-phenylpyrazoles from C(α)-dianions of carboalkoxyhydrazones and phenylhydrazones

The 1,4-dianions of C(α),N-carboalkoxyhydrazones and C(α),N-phenylhydrazones were prepared in an excess of lithium diisopropylamide (LDA). These dilithiated intermediates resulted from metalation of substituted hydrazones of several all-aliphatic cyclic ketones, aliphatic-aromatic cyclic ketones phenylacetaldehyde, and several substituted propiophenones or acetophenones. The esters utilized for Claisen-type condensations of these dianion intermediates included methyl salicylate, methyl p-hydroxybenzoate, methyl nicotinate and related materials. The condensations were followed by acid-cyclizations to give a variety of N-phenylpyrazoles and N-carboalkoxypyrazoles, most of which are new.
Interface surfaces for protein-protein complexes

Protein-protein interactions, which form the basis for most cellular processes, result in the formation of protein interfaces. Believing that the local shape of proteins is crucial, we take a geometric approach and present a definition of an interface surface formed by two or more proteins as a subset of their Voronoi diagram. The definition deals with the difficult and important problem of specifying interface boundaries by invoking methods used in the alpha shape representation of molecules, the discrete flow on Delaunay simplices to define pockets and reconstruct surfaces, and the assessment of the importance of topological features. We present an algorithm to construct the surface and define a hierarchy that distinguishes core and peripheral regions. This hierarchy is shown to have correlation with hot-spots in protein-protein interactions. Finally, we study the geometric and topological properties of interface surfaces and show their high degree of contortion.
Evaluation of Flip-Flop Jet Nozzles for Use as Practical Excitation Devices

This paper describes the flowfield characteristics of the flip-flop jet nozzle and the potential for using this nozzle as a practical excitation device. It appears from the existing body of published information that there is a lack of data on the parameters affecting the operation of such nozzles and on the mechanism of operation of these nozzles. An attempt is made in the present work to study the important parameters affecting the operation and performance of a flip-flop jet nozzle. Measurements were carried out to systematically assess the effect of varying the nozzle pressure ratio (NPR) as well as the length and volume of the feedback tube on the frequency of oscillation of this device. Flow visualization was used to obtain a better understanding of the jet flowfield and of the processes occurring within the feedback tube. The frequency of oscillation of the flip-flop jet depended significantly on the feedback tube length and volume as well as on the nozzle pressure ratio. In contrast, the coherent velocity perturbation levels did not depend on the above mentioned parameters. The data presented in this paper would be useful for modeling such flip-flop excitation devices that are potentially useful for controlling practical shear flows.
Leveraging tacit knowledge in alliances: The importance of using relational capabilities to build and leverage relational capital

Abstract Effectively managing existing tacit knowledge stocks and transferring knowledge between partners contributes to firm capabilities that allow them to differentiate their goods and services from those of their competitors. Because it also helps them to provide greater value to customers, it contributes to the development of a competitive advantage. In highly competitive industries, firms need to focus on proactively managing their knowledge resources to ensure survival. However, the knowledge management process is at times complex especially because of the difficulty involved in conveying tacit knowledge. Due to its latent potential for enabling firms to achieve potential competitive advantage, how firms utilize and transfer stocks of tacit knowledge requires enhanced understanding. In specific, we explain how firms use relational capabilities to build relational capital with partners. In turn, relational capital facilitates the transfer of tacit knowledge between collaborating partners. We develop several propositions regarding the factors likely to influence the transfer of a firm's tacit knowledge resources in strategic alliances. The importance of social capital's relational dimension, relational capital, in this process is highlighted.
Is SGR 1900+14 a Magnetar?

We present Rossi X-Ray Timing Explorer observations of the soft gamma-ray repeater SGR 1900+14 taken 1996 September 4-18, nearly 2 yr before the 1998 active period of the source. The pulsar period (P) of 5.1558199 ± 0.0000029 s and period derivative () of (6.0 ± 1.0) × 10-11 s s-1 measured during the 2 week observation are consistent with the mean of (6.126 ± 0.006) × 10-11 s s-1 over the time up to the commencement of the active period. This is less than half that of (12.77 ± 0.01) × 10-11 s s-1 observed during and after the active period. If magnetic dipole radiation were the primary cause of the pulsar spin-down, the implied neutron star magnetic field would exceed the critical field of ≈4.4 × 1013 G by more than an order of magnitude, and such field estimates for this and other soft gamma repeaters (SGRs) have been offered as evidence that the SGRs are magnetars, in which the neutron star magnetic energy exceeds the rotational energy. The observed doubling of , however, would suggest that the pulsar magnetic field energy increased by more than 100% as the source entered an active phase, which seems very hard to reconcile with models in which the SGR bursts are powered by the release of magnetic energy. Because of this, we suggest that the spin-down of SGR 1900+14 is not driven by magnetic dipole radiation, but by some other process, most likely a relativistic wind. The , therefore, does not provide a measure of the pulsar magnetic field strength, nor evidence for a magnetar.
Perfect fluid theory and its extensions

We review the canonical theory for perfect fluids in Euler's and Lagrange's formulations. The theory is related to a description of extended structures in higher dimensions. Internal symmetry and supersymmetry degrees of freedom are incorporated. Additional miscellaneous subjects that are covered include physical topics concerning quantization as well as mathematical issues of volume preserving diffeomorphisms and representations of Chern–Simons terms (= vortex or magnetic helicity).
Inclusion of Moisture Effect in Fatigue Test for Asphalt Pavements

Damage of asphalt mixes due to moisture is a complex phenomenon. Conventional moisture-related tests do not well simulate field conditions, in which traffic loading is an essential component. Flexural beam test has been widely used in current pavement design to evaluate material properties of asphalt mixes, but has not been well explored to study the moisture effect. This paper developed a typical fatigue-based test procedure for comparative evaluation of moisture sensitivity of different mixes. It is a controlled-strain flexural beam fatigue test performed at 20 degrees C, 10 Hz, and 200 me on specimens pre-saturated under 635 mm-HG vacuum for 30 minutes and preconditioned at 60 degrees C for one day. Test results showed that the fatigue based test procedure can distinguish mixes with different moisture sensitivities, and give a ranking of mixes consistent with prior field experience. An extension of the test procedure for use in the pavement design was also discussed, but further work is needed to implement the test procedure.
Synthesis of the Kopsia alkaloids (±)-pauciflorine B, (±)-lahadinine B, (±)-kopsidasine, (±)-kopsidasine-N-oxide, (±)-kopsijasminilam and (±)-11-methoxykopsilongine

Abstract Pictet–Spengler condensation of 13 with tryptamine gave 14 , which was converted into 17 . Treatment of 17 with phenyl chloroformate resulted in 18 , which underwent transannular cyclization to give 19 . The more stable cyano-analog 22 was made by treating 18 with Tf2O/DMAP to generate 18f , and quenching the reaction with trimethylsilyl cyanide. Treatment of 22 with acryloyl chloride (excess) at 75°C gave 23 , which was directly treated with N-hydroxy-2-thiopyridone/Et3N to give 24 . Irradiation of 24 in the presence of t-BuSH resulted in reductive decarboxylation to give 26 and a small amount of the 2-thiopyridyl ether 25 . Protection of the aniline nitrogen in 26 required the use of triphosgene/pyridine followed by methanol. The final step for the conversion of 27 into 28 required conjugate reduction of the α,β-unsaturated ester followed by α-hydroxylation and gave 28 (11,12-demethoxy lahadinine B). Exposure of 26 to PhI(OAc)2/MeOH cleanly gave 26a , which was directly reduced with Zn/AcOH to 29 . Conversion of 29 into 30 proceeded as before, and when 30 was treated with AgBF4/THF followed by aqueous NaHCO3 it was converted into (±)-kopsidasine 2 , completely characterized as its derived N-oxide 2a . Treatment of 26 with AgBF4/THF followed by aqueous NaHCO3, gave 31 . Oxidation of 31 with m-chloroperoxybenzoic acid resulted in the N-oxide 32 which underwent fragmentation to give 33 when exposed to trifluoroacetic anhydride. When the diene 33 was treated with Mn(dpm)3 (cat)/PhSiH3/O2 in isopropyl alcohol at 0°C, it was converted into kopsijasminilam 4 . Peracetic acid in EtOAc (10%) was used to quench the AgBF4/THF conversion of 28 into 37 , and resulted in 42 / 42a (4:1, 65%) along with small amounts of 38 and 41c . Application of these procedures, with some modifications, to the 11,12-dimethoxy substituted systems gave (±)-lahadinine B 64 . Treatment of 64 with triethylsilane in the presence of trifluoroacetic acid cleanly converted it into 11-methoxykopsilongine 65 (93%). Treatment of (±)-lahadinine B 64 with AgBF4/THF followed by work-up with EtOAc/MeCO3H (10%) gave (±)-pauciflorine 6 and the double bond isomer 6a .
Palladium-Catalyzed Carbonylative Cyclization of 1-Iodo-2-alkenylbenzenes

The Pd-catalyzed carbonylation of ω-vinyl-substituted o-iodoalkenylbenzenes 1−4 can provide up to modest yields (50−60%) of 5- and 6-membered Type I cyclic acylpalladation products, i.e., α,β-unsaturated cyclic ketones, in the absence of an external nucleophile and high yields of 5- and 6-membered Type II cyclic acylpalladation products, i.e., α- or β-((alkoxycarbonyl)methyl)substituted cyclic ketones in the presence of an alcohol, e.g., MeOH. In cases where no such processes are available, other side reactions, such as cyclic carbopalladation, polymeric acylpalladation, and trapping of acylpalladiums via esterification and other processes may become predominant. Neither smaller, i.e., 3- or 4-membered, nor 7-membered or larger cyclic ketones appear to be accessible by the reaction. In most cases, the exo-mode cyclic acylpalladation takes place exclusively. However, the cyclic acylpalladation of 3 proceeds exclusively via endo-mode cyclization to give 5-membered ketones. Substitution of one or more hydrog...
A limit theorem for products of free unitary operators

This paper establishes necessary and sufficient conditions for the sequence of products of freely independent unitary operators to converge in distribution to the uniform law on the unit circle.
Minimizing Geometric Isomerization During Oxidation of Allylic Alcohols to Aldehydes

Abstract Oxidation of allylic alcohols with MnO2/Na2CO3 gives from 20:1 to 99:1 selectivity for the geometrically retained enals, whereas MnO2 alone gives 10% or more of the isomerized enals.
The Aptly Named Phoenix Dwarf Galaxy

The Local Group galaxy Phoenix has the properties of a dwarf spheroidal galaxy, but an adjacent H I cloud has been recently found to be at the same radial velocity as the stars. The proximity suggests that this cloud is associated with the most recent (≤100 Myr) star formation in Phoenix. We have obtained relatively high sensitivity and high resolution H I imaging with the VLA with the goal of distinguishing between different processes for displacing the gas from the galaxy. Due to the outer curvature of the H I cloud, it appears that expulsion from the galaxy by winds from supernovae is more likely than ram pressure stripping. The isolation of the galaxy makes tidal stripping highly unlikely. Using a star formation history constructed from HST imaging, we construct a simple kinematic model that implies that the H I cloud is still gravitationally bound to the galaxy. Gas that is expelled from the centers of dwarf galaxies but remains gravitationally bound may explain the episodic star formation observed in several dwarfs. In the specific case of Phoenix, there may be future star formation in this currently dSph-like galaxy.
Precursor Environmental Conditions Associated with the Termination of Madden–Julian Oscillation Events

AbstractThis study presents an analysis of the precursor environmental conditions related to the termination of Madden–Julian oscillation (MJO) events. A simple climatology is created using a real-time MJO monitoring index, documenting the locations and frequencies of MJO decay. Lead–lag composites of several atmospheric variables including temperature, moisture, and intraseasonal wind anomalies are generated from three reanalyses. There is remarkable agreement among the datasets with long-term, lower-tropospheric moisture deficits over the local domain best identifying termination events over the Indian Ocean. MJO termination in the Indian Ocean is also linked to a northward shift of the intertropical convergence zone (ITCZ) with possible lead times as much as 20 days prior to MJO decay.Statistically significant differences in the low-level vertical velocity and specific humidity are also identified more than 10 days in advance of MJO termination events in the western Pacific, though the differences here...