Frustration driven stock market dynamics: Leverage effect and asymmetry

By applying inverse statistics to financial data it has recently been found from empirical studies that indices exhibit a pronounced gain-loss asymmetry [M.H. Jensen, Phys. Rev. Lett. 83 (1999) 76; I. Simonsen, M.H. Jensen, A. Johansen, Eur. Phys. J. B 27 (2002) 583; M.H. Jensen, A. Johansen, I. Simonsen, Physica A 324 (2003) 338]. This gain-loss asymmetry appears to have some similarities with the stylized fact leverage effect and we investigate if they could be of same origin. For this purpose we introduce the Frustration Governed Market model which includes correlations in time between a model index and its individual stocks. It is shown that the model reproduces very well the empirical findings with respect to gain-loss asymmetry and leverage. In special cases, however, the model may produce leverage without a pronounced gain-loss asymmetry.     

Tetrathiafulvalene-functionalized triptycenes: synthetic protocols and elucidation of intramolecular Coulomb repulsions in the oxidized species

A large selection of triptycenes functionalized with tetrathiafulvalene (TTF) units as well as triptycenes containing extended TTFs as a part of the triptycene core have been synthesized utilizing new triptycene di- and tetraaldehydes as well as bis-, tetrakis- and hexakis(bromomethyl) derivatives. The largest scaffold contains a total of 12 TTFs around the central triptycene core. From spectroelectrochemical and chemical oxidation studies, we have elucidated the extent to which an increasing number of electrostatic interactions among oxidized TTF units exert an influence on the absorption characteristics.     

Highly enantioselective hydrosilylation of aromatic alkenes

Currently, the most effective and economic way to convert an alkene into an optically active alcohol is the two-step sequence: hydrosilylation/oxidation. Much work has been devoted to elucidating effective catalysts for this process, but hitherto only one effective and highly stereoselective process has been available. Herein we present a novel catalytic system for the asymmetric hydrosilylation of aromatic alkenes, giving the products in high yields and with the highest enantioselectivity (up to 99% ee) ever observed for this reaction. The reaction works efficiently for a variety of substituted aromatic alkenes, giving access after Tamao oxidation to almost optically pure benzylic alcohols in high yields.     

Crystal and molecular structure of benzoyl-l-leucyl-glycine ethyl ester (l-LEUGLY)

The crystal structure of the dipeptide derivative benzoyl-l-leucylglycine ethyl ester has been determined by direct methods (Multan 78), and refined by fullmatrix least squares toR=0.092 for 1638 reflections;I>3(I), CuK radiation. The space group isP2₁2₁2₁,a=20.679(7),b=16.440(6),c=11.034(5) Å,Z=8. Disorder observed in the ethyl ester and leucyl side-chains of the two independent molecules per asymmetric unit probably accounts, at least partially, for the weak diffracting power of the crystals. Both molecules exhibit markedly coiled hydrogen-bonded conformations. An attempt was made to obtain improved hydrogen bond geometry by the use of neutron diffraction data.     

Sensitive determination of monoamine neurotransmitters,their main metabolites and precursor amino acids in different mouse brain components by liquid chromatography–electrospray tandem mass spectrometry after selective sample clean‐up

For the assessment of diets and supplements formulated for the treatment of phenylketonuria, a highly sensitive and selective method was developed and validated for the quantification of dopamine (DA), serotonin (5‐HT), 3,4‐dihydroxyphenylacetic acid (DOPAC), 5‐hydroxyindoleacetic acid (5‐HIAA), phenylalanine, tyrosine and tryptophan in mouse cerebellum, brain stem, hypothalamus, parietal cortex, anterior piriform cortex and bulbus olfactorius. Samples were extracted by deproteinization with acetonitrile, and the extracts were cleaned up by strong anion exchange and weak cation exchange applied sequentially. The substances were detected by rapid liquid chromatography tandem mass spectrometry. Matrix components were largely removed by the clean‐up, resulting in low matrix effects. The lower limits of quantification for an extracted tissue mass of 100 mg were 0.3, 0.3, 0.2 and 2 ng/g for DA, 5‐HT, 5‐HIAA and DOPAC, respectively. The mean true extraction recoveries were 80–102%. The relative intra‐laboratory reproducibility standard deviations were generally <11% at concentrations of 20–1000 ng/g for DA, 5‐HT, 5‐HIAA and DOPAC and 7% at concentrations of 5–50 μg/g for the amino acids. This method was successfully used in a phenylketonuria mice study including nearly 300 brain tissue samples and for small sample masses (for example, 2 mg of bulbus olfactorius).     

Electrochemical performance and stability of nano-particulate and bi-continuous La1−X Sr X CoO3 and Ce0.9Gd0.1O1.95 composite electrodes

A bi-continuous porous cathode consisting of nano-particles of strontium substituted lanthanum cobaltite (LSC) covering the surface of a Ce_0.9Gd_0.1O_1.95 (CGO10) backbone has been produced. The polarization resistance (R _P) of this cathode was measured to ～35 mΩ cm² at 650 °C. The area-specific resistance at 650 °C (ASR) when applied onto an anode supported cell (ASC) was found to increase from 540 to 730 mΩ cm² when subjected to a thermal cycle to 850 °C. This effect was attributed to particles coarsening but also to a reaction with the electrolyte. The results imply that a CGO10 barrier is required for this type of nano-structured cathode.     

Purity Determination of Phosphorus Compounds by Internat- Standard31 P Nmr Spectroscopy. an Experimental Study and Validation

Abstract

Due to the proportionality between the area of the NMR signal and the number of nuclei, internal standard³¹P NMR spectroscopy is in principle a rapid and simple method for determination of the purity of phosphorus compounds.nuclei, internal standard³¹P NMR spectroscopy is in principle a rapid and simple method for determination of the purity of phosphorus compounds.nuclei, internal standard³¹P NMR spectroscopy is in principle a rapid and simple method for determination of the purity of phosphorus compounds.nuclei, internal standard³¹P NMR spectroscopy is in principle a rapid and simple method for determination of the purity of phosphorus compounds.     

Synthesis of dithiafulvene–quinone donor–acceptor systems: isolation of a Michael adduct

π‐Conjugated donor–acceptor systems based on dithiafulvene (DTF) donor units and various acceptor units have attracted attention for their linear and nonlinear optical properties. The reaction between p‐benzoquinone and a 1,3‐dithiole phosphonium salt, deprotonated by lithium hexamethyldisilazide (LiHMDS), gave a product mixture from which the Michael adduct [systematic name: dimethyl 2‐(3‐hydroxy‐6‐oxocyclohexa‐2,4‐dien‐1‐ylidene)‐2H‐1,3‐dithiole‐4,5‐dicarboxylate], C₁₃H₁₀O₆S₂, was isolated. It is likely that one of the unidentified products obtained previously by others from related reactions could be a similar Michael adduct.