Catalytic Role of Metal Oxides in Gold-Based Catalysts: A First Principles Study of CO Oxidation on TiO2 Supported Au

CO oxidation on TiO2 supported Au has been studied using density functional theory calculations. Important catalytic roles of the oxide have been identified: (i) CO oxidation occurs at the interface between Au and the oxide with a very small barrier; and (ii) O-2 adsorption at the interface is the key step in the reaction. The physical origin of the oxide promotion effect has been further investigated: The oxide enhances electron transfer from the Au to the antibonding states of O-2, giving rise to (i) strong ionic bonding between the adsorbed O-2, Au, and the Ti cation; and (ii) a significant activation of O-2 towards CO oxidation.

Power-law behaviour, heterogeneity, and trend chasing

Long-range dependence in volatility is one of the most prominent examples in financial market research involving universal power laws. Its characterization has recently spurred attempts to provide some explanations of the underlying mechanism. This paper contributes to this recent line of research by analyzing a simple market fraction asset pricing model with two types of traders---fundamentalists who trade on the price deviation from estimated fundamental value and trend followers whose conditional mean and variance of the trend are updated through a geometric learning process. Our analysis shows that agent heterogeneity, risk-adjusted trend chasing through the geometric learning process, and the interplay of noisy fundamental and demand processes and the underlying deterministic dynamics can be the source of power-law distributed fluctuations. In particular, the noisy demand plays an important role in the generation of insignificant autocorrelations (ACs) on returns, while the significant decaying AC patterns of the absolute returns and squared returns are more influenced by the noisy fundamental process. A statistical analysis based on Monte Carlo simulations is conducted to characterize the decay rate. Realistic estimates of the power-law decay indices and the (FI)GARCH parameters are presented.

Heterogeneity, convergence, and autocorrelations

This paper is a contribution to the literature on the explanatory power and calibration of heterogeneous asset pricing models. We set out a new stochastic market-fraction asset pricing model of fundamentalists and trend followers under a market maker. Our model explains key features of financial market behaviour such as market dominance, convergence to the fundamental price and under- and over-reaction. We use the dynamics of the underlying deterministic system to characterize these features and statistical properties, including convergence of the limiting distribution and autocorrelation structure. We confirm these properties using Monte Carlo simulations.

Molecular cloning of mRNA from toad granular gland secretion and lyophilized skin: identification of Bo8 - a novel prokineticin from Bombina orientalis

Prokineticins are small (8 kDa), biologically active secretory proteins whose primary structures have been highly conserved throughout the Animal Kingdom. Representatives have been identified in the defensive skin secretions of several amphibians reflecting the immense structural/functional diversity of polypeptides in such. Here we describe the identification of a prokineticin homolog (designated Bo8) from the skin secretion of the Oriental fire-bellied toad (Bombina orientalis). Full primary structural characterization was achieved using a combination of direct Edman microsequencing, mass spectrometry and cloning of encoding skin cDNA. The latter approach employed a recently described technique that we developed for the cloning of secretory peptide cDNAs from lyophilized skin secretion, and this was further extended to employ lyophilized skin as the starting material for cDNA library construction. The Bo8 precursor was found to consist of an open-reading frame of 96 amino acid residues consisting of a putative 19-residue signal peptide followed by a single 77-residue prokineticin (Mr = 7990 Da). Amino acid substitutions in skin prokineticins from the skin secretions of bombinid toads are confined to discrete sites affording the necessary information for structure/activity studies and analog design.