Effects of moderate abundance changes on the atmospheric structure and colours of Mira variables (Research Note)

Aims. We study the effects of moderate deviations from solar abundances upon the atmospheric structure and colours of typical Mira variables. Methods. We present two model series of dynamical opacity-sampling models of Mira variables which have (1) 1 solar metallicity 3 and (2) "mild" S-type C/O abundance ratio ([C/O]=0.9) with typical Zr enhancement (solar +1.0). These series are compared to a previously studied solar-abundance series which has similar fundamental parameters (mass, luminosity, period, radius) that are close to those of o Cet. Results. Both series show noticeable effects of abundance upon stratifications and infrared colours but cycle-to-cycle differences mask these effects at most pulsation phases, with the exception of a narrow-water-filter colour near minimum phase.Comment: 4 pages, 3 figures, accepted for A&

Bilinear Fractal Interpolation and Box Dimension

In the context of general iterated function systems (IFSs), we introduce bilinear fractal interpolants as the fixed points of certain Read-Bajraktarevi\'{c} operators. By exhibiting a generalized "taxi-cab" metric, we show that the graph of a bilinear fractal interpolant is the attractor of an underlying contractive bilinear IFS. We present an explicit formula for the box-counting dimension of the graph of a bilinear fractal interpolant in the case of equally spaced data points

Asset Pricing with Observable Stochastic Discount Factors.

The stochastic discount factor model provides a general framework for pricing assets. By specifying the discount factor suitably it encompasses most of the theories currently in use, including CAPM and consumption CAPM. The SDF model has been based on the use of single and multiple factors, and on latent and observed factors. In most situations, and especially for the term structure, single factor models are inappropriate, whilst latent variables require the somewhat arbitrary specification of generating processes and are difficult to interpret. In this paper we survey the principal different implementations of the SDF model for FOREX, equity and bonds and we propose a new approach. This is based on the use of multiple factors that are observable and modelling the joint distribution of excess returns and the factors using a multi-variate GARCH-in-mean process. We argue that in general single equation and VAR models, although widely used in empirical finance, are inappropriate as they do not satisfy the no-arbitrage condition. Since risk premia arise from conditional covariation between returns and the factors, both a multi-variate context and having conditional covariances in the conditional mean process, is essential. We explain how apparent exceptions, such as the CIR and Vasicek models, in fact meet this requirement - but at a price. We explain our new approach, discuss how it might be implemented and present some empirical evidence, mainly from our own researches. Partly, to enable comparisons to be made, the survey also includes evidence from recent empirical work using more traditional approaches.Asset Pricing; Stochastic Discount Factors; Forex; Equity Term Structure; Affine Factor Models; Consumption CAPM; Financial Econometrics; GARCH

Electron Transfer-oxy Radical Mechanism for Anti-cancer Agents: 9-anilinoacridines

A possible mode of action involving electron transfer is advanced for the 9- anilinoacridines. The mechanism entails formation of toxic oxy radicals which destroy the neoplasm. Cyclic voltammetry was performed on iminium type ions derived by protonation of the acridines. Reductions were generally reversible with potentials of about - 0.60 V. Involvement of quinoidal metabolites is also a possibility. The relationship of electrochemical behavior to structure and physiological activity is addressed

A combined SNIFTIRS and XANES study of electrically polarised copper electrodes in DMSO and DMF solutions of cyanate (NCO⁻), thiocyanate (NCS⁻) and selenocyanate (NCSe⁻) ions

A SNIFTIRS (subtractively normalized interfacial Fourier transform infrared spectroscopy) and X-ray absorption spectroscopy (XAS) study of electrically polarized copper electrodes in six polar aprotic solvent-based systems is presented. In the systems investigated, i.e. dimethyl formamide (DMF) and dimethyl sulfoxide (DMSO) solutions containing pseudohalide species of cyanate (NCO⁻), thiocyanate (NCS⁻) and selenocyanate (NCSe⁻) codissolved with tetrabutylammonium perchlorate (TBAP), Cu was found to dissolve over a wide range of potentials to produce the corresponding Cu(I) pseudohalide and/or Cu(II) pseudohalide complex ion species. Insoluble deposited films were also observed at higher anodic applied potentials, thought to be CuSCN in the Cu/NCS⁻/DMSO or DMF systems, and solid K(SeCN)₃ in the Cu/NCSe⁻/DMSO or DMF systems respectively. The presence of the Cu(II) and/or Cu(I) oxidation states in complexes formed by polarization in Cu/pseudohalide ion systems in DMSO was clearly proven using XAS of cell solutions sampled after SNIFTIRS/electrical polarization experiments. In addition, Fourier transform infrared (FTIR) and X-ray absorption near edge spectroscopy (XANES) data obtained from model solutions prepared from mixing Cu(I) and/or Cu(II) salts with the respective pseudohalide ions in DMF and DMSO confirmed the speciation observed in the electrochemical experiments

Housing markets and independence in old age: expanding the opportunities

This report highlights the benefits of specialised private retirement accommodation and recommends a number of simple policy changes at no cost to the public purse to help increase its supply and address the challenges of housing an ageing population

Decay of Ultralight Axion Condensates

Axion particles can form macroscopic condensates, whose size can be galactic in scale for models with very small axion masses $m\sim10^{-22}$ eV, and which are sometimes referred to under the name of Fuzzy Dark Matter. Many analyses of these condensates are done in the non-interacting limit, due to the weakness of the self-interaction coupling of axions. We investigate here how certain results change upon inclusion of these interactions, finding a decreased maximum mass and a modified mass-radius relationship. Further, these condensates are, in general, unstable to decay through number-changing interactions. We analyze the stability of galaxy-sized condensates of axion-like particles, and sketch the parameter space of stable configurations as a function of a binding energy parameter. We find a strong lower bound on the size of Fuzzy Dark Matter condensates which are stable to decay, with lifetimes longer than the age of the universe.Comment: 24 pages, 2 figures. v2: Added brief discussion of angular momentum; extended Appendix A; typos correcte