Subset threshold autoregression

We develop in this paper an efficient way to select the best subset threshold autoregressive model. The proposed method uses a stochastic search idea. Differing from most conventional approaches, our method does not require us to fix the delay or the threshold parameters in advance. By adopting the Markov chain Monte Carlo techniques, we can identify the best subset model from a very large of number of possible models, and at the same time estimate the unknown parameters. A simulation experiment shows that the method is very effective. In its application to the US unemployment rate, the stochastic search method successfully selects lag one as the time delay and five best models from more than 4000 choices. Copyright © 2003 John Wiley & Sons, Ltd.     

The Huntington's disease candidate region exhibits many different haplotypes.

Analysis of 78 Huntington's disease (HD) chromosomes with multi-allele markers revealed 26 different haplotypes, suggesting a variety of independent HD mutations. The most frequent haplotype, accounting for about one third of disease chromosomes, suggests that the disease gene is between D4S182 and D4S180. However, the paucity of an expected class of chromosomes that can be related to this major haplotype by assuming single crossovers may reflect the operation of other mechanisms in creating haplotype diversity. Some of these mechanisms sustain alternative scenarios that do not require a multiple mutational origin for HD and/or its positioning between D4S182 and D4S180.     

Characterization of the rough endoplasmic reticulum ribosome-binding activity.

The rough endoplasmic reticulum membranes of mammalian cells contain specific ribosome-binding sites. A purification to apparent homogeneity of a negatively charged protein (ERp180) of relative molecular mass 180,000 (180 K) was reported which was proposed to function as a rough endoplasmic reticulum ribosome receptor. We report here that ribosome-binding site activity quantitatively solubilized from rough endoplasmic reticulum membranes does not cofractionate with ERp180. By contrast, ribosome-binding site activity fractionates as a much smaller, positively charged protein.     

Darstellung doppelbrechender Lipoidtropfen aus dem Serum

Summary (1) Doubly refracting lipoid droplets can be demonstrated in normal and pathological sera by means of alcohol ether extraction. This is not possible with ether extraction alone.(2) These lipoid droplets can be demonstrated only, or almost only, when they are precipitated out of alcohol or ether alcohol     

Oberflächenspannung und Schallgeschwindigkeit

Summary The preceding empirical relation was found between the surface tension of liquids, the specific weight of liquids, and the velocity of sound:=6.3 · 10^{–4 3/2}. In place of the vèocity of sound can be used, with suitable changes in the equation, the compressibility or, in the case of solid substances, the elasticity of the material in question. The range of validity of this relation is so large that it is possible by means of it to calculate the surface tension of solid substances and of gases.