Quantum Counterfactuals and Locality

Stapp's counterfactual argument for quantum nonlocality based upon a Hardy entangled state is shown to be flawed. While he has correctly analyzed a particular framework using the method of consistent histories, there are alternative frameworks which do not support his argument. The framework dependence of quantum counterfactual arguments, with analogs in classical counterfactuals, vitiates the claim that nonlocal (superluminal) influences exist in the quantum world. Instead it shows that counterfactual arguments are of limited use for analyzing these questions.Comment: 8 pages, 1 PSTricks figur

Passage of Large Fish Around a Causeway in Prudhoe Bay, Alaska

Fish movements around a 2.8 km solid-fill causeway in Prudhoe Bay, Alaska, were examined by tagging anadromous least and arctic cisco (>220 mm) on each side of the causeway in summer and comparing the recapture ratios when the fish were later caught in the Colville Delta commercial fishery 80 km to the west. There was no significant difference in proportions of recaptures among fish (species combined) that did not have to swim around the causeway. Thus available data indicate that the net movements of large least cisco, and probably arctic cisco, were unaffected by this man-made coastal feature.Key words: least cisco, Coregonus sadinella, arctic cisco, Coregonus autumnalis, movements, Beaufort Se

Controlling competitive and synergistic interactions in formulations

Amphiphilic block copolymers of the poly (ethylene oxide)–poly (propylene oxide) (PEO–PPO) group (commercially available as Pluronic or Poloxamers) are widely used in numerous applications, especially the pharmaceutical, consumer, technological and formulation areas. Whilst mixtures of small molecule surfactants and Pluronics have previously been examined, as has the effect of alcohols on Pluronic behavior, there are far fewer studies of the quaternary systems; Pluronic/small molecule surfactants/alcohol/water. Against this background, we have employed a range of techniques including surface tension, pulsed gradient spin-echo nuclear magnetic resonance (PGSE-NMR) and small- angle neutron scattering (SANS) to quantify the interaction between these small molecule surfactants (sodium dodecyl sulphate, dodecyltrimethylammonium bromide and polyoxyethylene (23) lauryl ether) and short, medium and long chain alcohols (ethanol, hexanol and decanol respectively) on the critical micelle concentration (CMC) and subsequently the micellar structure. SANS data for aqueous Pluronic solutions with added alcohols fitted to a charged spherical core/shell model for the micelle. The addition of the surfactants led to significantly smaller, oblate elliptical mixed micelles in the absence of alcohols. Addition of ethanol to the system led to a decrease in the micelle size, whereas larger micelles were observed upon addition of longer chain alcohols. NMR studies provided a complementary estimate of the micelle composition using average diffusion coefficients. These observations extend our understanding of the synergistic interactions between the Pluronic and small molecule surfactants when the partitioning of the added alcohol perturbs the interaction between the two types of surfactants. Please click Additional Files below to see the full abstract

Prepotential and Instanton Corrections in N=2 Supersymmetric SU(N_1)xSU(N_2) Yang Mills Theories

In this paper we analyse the non-hyperelliptic Seiberg-Witten curves derived from M-theory that encode the low energy solution of N=2 supersymmetric theories with product gauge groups. We consider the case of a SU(N_1)xSU(N_2) gauge theory with a hypermultiplet in the bifundamental representation together with matter in the fundamental representations of SU(N_1) and SU(N_2). By means of the Riemann bilinear relations that hold on the Riemann surface defined by the Seiberg--Witten curve, we compute the logarithmic derivative of the prepotential with respect to the quantum scales of both gauge groups. As an application we develop a method to compute recursively the instanton corrections to the prepotential in a straightforward way. We present explicit formulas for up to third order on both quantum scales. Furthermore, we extend those results to SU(N) gauge theories with a matter hypermultiplet in the symmetric and antisymmetric representation. We also present some non-trivial checks of our results.Comment: 21 pages, 2 figures, minor changes and references adde

Impulsive waves in the Nariai universe

A new class of exact solutions is presented which describes impulsive waves propagating in the Nariai universe. It is constructed using a six-dimensional embedding formalism adapted to the background. Due to the topology of the latter, the wave front consists of two non-expanding spheres. Special sub-classes representing pure gravitational waves (generated by null particles with an arbitrary multipole structure) or shells of null dust are analyzed in detail. Smooth isometries of the metrics are briefly discussed. Furthermore, it is shown that the considered solutions are impulsive members of a more general family of radiative Kundt spacetimes of type-II. A straightforward generalization to impulsive waves in the anti-Nariai and Bertotti-Robinson backgrounds is described. For a vanishing cosmological constant and electromagnetic field, results for well known impulsive pp-waves are recovered.Comment: 9 pages, 4 figures, REVTeX 4. v3: added Appendix B, revised references, minor changes in the text. To appear in Phys. Rev.

Probing the surfaces of core-shell and hollow nanoparticles by solvent relaxation NMR

Measurement of the spin-spin NMR relaxation time (or its inverse, the rate) of water molecules in aqueous nanoparticle dispersions has become a popular approach to probe of the nature and structure of the particle surface and any adsorbed species. Here, we report on the characterisation of aqueous dispersions of hollow amorphous nanoparticles, that have two liquid accessible surfaces (inner cavity surface and outer shell surface), plus the solid (silica) and core-shell (titania-silica) nanoparticle precursors from which the hollow particles have been prepared. In all cases, the observed water relaxation rates scale linearly with particle surface area, with the effect being more pronounced with increasing levels of titania present at the particle surface. Two distinct behaviours were observed for the hollow nanoparticles at very low volume fractions, which appear to merge with increasing surface area (particle concentration). Herewith, we further show the versatility of solvent NMR spectroscopy as a probe of surface character

A metalloproteomic analysis of interactions between plasma proteins and zinc: elevated fatty acid levels affect zinc distribution

Serum albumin is a highly abundant plasma protein associated with the transport of metal ions, pharmaceuticals, fatty acids and a variety of small molecules in the blood. Once thought of as a molecular ‘sponge’, mounting evidence suggests that the albumin-facilitated transport of chemically diverse entities is not independent. One such example is the transport of Zn2+ ions and non-esterified ‘free’ fatty acids (FFAs) by albumin, both of which bind at high affinity sites located in close proximity. Our previous research suggests that their transport in blood plasma is linked via an allosteric mechanism on serum albumin. In direct competition, albumin-bound FFAs significantly decrease the binding capacity of albumin for Zn2+, with one of the predicted consequences being a change in plasma/serum zinc speciation. Using liquid chromatography (LC), ICP-MS and fluorescence assays, our work provides a quantitative assessment of this phenomenon, and finds that in the presence of high FFA concentrations encountered in various physiological conditions, a significant proportion of albumin-bound Zn2+ is re-distributed amongst plasma/serum proteins. Using peptide mass fingerprinting and immunodetection, we identify candidate acceptor proteins for Zn2+ liberated from albumin. These include histidine-rich glycoprotein (HRG), a multifunctional protein associated with the regulation of blood coagulation, and members of the complement system involved in the innate immune response. Our findings highlight how FFA-mediated changes in extracellular metal speciation might contribute to the progression of certain pathological conditions

Sentiment analysis and the impact of employee satisfaction on firm earnings

Prior text mining studies of corporate reputational sentiment based on newswires, blogs and Twitter feeds have mostly captured reputation from the perspective of two groups of stakeholders – the media and consumers. In this study we examine the sentiment of a potentially overlooked stakeholder group, namely, the firm’s employees. First, we present a novel dataset that uses online employee reviews to capture employee satisfaction. We employ LDA to identify salient aspects in employees’ reviews, and manually infer one latent topic that appears to be associated with the firm’s outlook. Second, we create a composite document by aggregating employee reviews for each firm and measure employee sentiment as the polarity of the composite document using the General Inquirer dictionary to count positive and negative terms. Finally, we define employee satisfaction as a weighted combination of the firm outlook topic cluster and employee sentiment. The results of our joint aspect-polarity model suggest that it may be beneficial for investors to incorporate a measure of employee satisfaction into their method for forecasting firm earnings

Rainich theory for type D aligned Einstein-Maxwell solutions

The original Rainich theory for the non-null Einstein-Maxwell solutions consists of a set of algebraic conditions and the Rainich (differential) equation. We show here that the subclass of type D aligned solutions can be characterized just by algebraic restrictions.Comment: 12 pages; v2: appendix with notatio