15 research outputs found
The English medieval first-floor hall: part 2 – The evidence from the eleventh to early thirteenth century
The concept of the first-floor hall was introduced in 1935, but Blair’s paper of 1993 cast doubt on many of those buildings which had been identified as such. Following the recognition of Scolland’s Hall, Richmond Castle as an example of a hall at first-floor level, the evidence for buildings of this type is reviewed (excluding town houses and halls in the great towers of castles, where other issues apply). While undoubtedly a number of buildings have been mistakenly identified as halls, there is a significant group of structures which there are very strong grounds to classify as first-floor halls. The growth of masonry architecture in elite secular buildings, particularly after the Norman Conquest, allowed halls to be constructed on the first floor. The key features of these are identified and the reasons for constructing the hall at this level – prestige and security – are recognized. The study of these buildings allows two further modifications to the Blair thesis: in some houses, halls and chambers were integrated in a single block at an early date, and the basic idea of the medieval domestic plan was already present by the late eleventh century
Influence of water quality on nitrifier regrowth in two full-scale drinking water distribution systems
Xbra3 induces mesoderm and neural tissue in Xenopus laevis
AbstractHomologues of the murine Brachyury gene have been shown to be involved in mesoderm formation in several vertebrate species. In frogs, the Xenopus Brachyury homologue, Xbra, is required for normal formation of posterior mesoderm. We report the characterisation of a second Brachyury homologue from Xenopus, Xbra3, which has levels of identity with mouse Brachyury similar to those of Xbra. Xbra3 encodes a nuclear protein expressed in mesoderm in a temporal and spatial manner distinct from that observed for Xbra. Xbra3 expression is induced by mesoderm-inducing factors and overexpression of Xbra3 can induce mesoderm formation in animal caps. In contrast to Xbra, Xbra3 is also able to cause the formation of neural tissue in animal caps. Xbra3 overexpression induces both geminin and Xngnr-1, suggesting that Xbra3 can play a role in the earliest stages of neural induction. Xbra3 induces posterior nervous tissue by an FGF-dependent pathway; a complete switch to anterior neural tissue can be effected by the inhibition of FGF signalling. Neither noggin, chordin, follistatin, nor Xnr3 is induced by Xbra3 to an extent different from their induction by Xbra nor is BMP4 expression differentially affected
The role of facilitation in seedling recruitment and survival patterns, in the Strandveld Succulent Karoo, South Africa
Changes in bacterial community of anthracene bioremediation in municipal solid waste composting soil*
Polycyclic aromatic hydrocarbons (PAHs) are common contaminants in a municipal solid waste (MSW) composting site. Knowledge of changes in microbial structure is useful to identify particular PAH degraders. However, the microbial community in the MSW composting soil and its change associated with prolonged exposure to PAHs and subsequent biodegradation remain largely unknown. In this study, anthracene was selected as a model compound. The bacterial community structure was investigated using terminal restriction fragment length polymorphism (TRFLP) and 16S rRNA gene clone library analysis. The two bimolecular tools revealed a large shift of bacterial community structure after anthracene amendment and subsequent biodegradation. Genera Methylophilus, Mesorhizobium, and Terrimonas had potential links to anthracene biodegradation, suggesting a consortium playing an active role