Families of Roles: A new theory of occurrent-dependent roles

PublishedRoles are important both theoretically and practically for modelling the world around us. Although many theories of roles have been proposed, there remain aspects which are little understood. In this paper we investigate roles and their contexts from a temporal point of view.We introduce the idea of a family of occurrent-dependent roles as a means to organise prospective and retrospective derived roles around an original role from which they are derived. By this means we account for the existence of groups of similar roles which are difficult to distinguish without a careful analysis of the temporal aspects. Following detailed informal discussion, we present a preliminary formalisation of the key concepts and relations.Air Force Research Laborator

Angle-resolved photoemission spectroscopy of Co-based boride superconductor LaCo1.73Fe0.27B2

We have performed angle-resolved photoemission spectroscopy of Co-based boride superconductor LaCo1.73Fe0.27B2 (Tc = 4.1 K), which is isostructural to the 122-type Fe-pnictide superconductor with the pnictogen atom being replaced with boron. We found that the Fermi level is located at a dip in the density of states (DOS) in contrast to Co-pnictide ferromagnets. This reduction in DOS together with the strong Co 3d-B 2p covalent bonding removes the ferromagnetic order and may cause the superconductivity. The energy bands near the Fermi level show higher three dimensionality and a weaker electron-correlation effect than those of Fe pnictides. The Fermi surface topology is considerably different from that of Fe pnictides, suggesting the difference in the superconducting mechanism between boride and pnictide superconductors.Comment: 5 pages, 4 figure

Genome scan of BTA1 for QTL affecting weaning weight, yearling weight and post-weaning growth in Japanese Black cattle

A genome scan for chromosomal regions of bovine chromosome one (BTA1) influencing weaning weight (WT6), yearling weight (WT12) and post-weaning average daily gain (PWADG) was performed using 112 half-sib progeny of 4 Japanese Black (Wagyu) sires and 98 microsatellite DNA markers. Identity-By-Descent (IBD) probabilities at specific chromosomal locations from multiple marker data were determined and a linear model containing the fixed effects of sex, parity and season of birth as well as age as a covariate, was fitted to the IBD coefficients and phenotypic data. Data were analysed by generating an F-statistic by the regression of phenotype on the IBD probabilities of inheriting an allele from the sire. Permutation tests at chromosome-wide significance thresholds were carried out over 1, 000 iterations at 1cM intervals while the boostrap with resampling procedure was followed to estimate confidence intervals and average QTL locations. All these procedures were implemented in the QTL Express Computer programme with a web-based user interface (available at: http://qtl.cap.ed.ac.uk/). A significant QTL (P chromosome-wise threshold = 0.05) for PWADG was identified in Sires 2 and 3 located at 27cM and 29cM (95% confidence intervals of the QTL locations being 0-132cM and 0-125cM) respectively. Another QTL for WT12 was identified at 113cM in Sire 2. No significant effect on WT6 was detected in any of the sires. Selection indices that include QTL with accurately estimated effects on carcass characteristics could reduce the amount of lengthy and costly data collection by providing a means of genetic evaluation early in the life cycle. Since PWADG is positively correlated with WT6 and WT12 in beef cattle, the identification of these QTL in Japanese Black Cattle holds a high prospect for the implementation of marker-assisted selection for the early attainment of slaughter weight in this breed