186 resultados para Lloyd Gaines
Resumo:
The mid-fourteenth century map of Britain known as the ‘Gough’ map is the earliest extant depiction of the island in geographically recognizable form. Hitherto, however, interest in the road or route patterns marked on the map has meant that the map's extraordinarily rich settlement geography has not received the attention it merits and that, consequently, the point of the map may have been missed. The availability of a digital scan of the map coupled with the use of Geographical Information System (GIS) software provides the opportunity for a new look at the Gough map and the questions it poses. Attention in this article is directed to the settlement geography it shows, and in particular to the map's 654 cities, towns, villages, castles and monasteries. Their geographical positions as given on the manuscript are compared with their modern equivalents to shed light on some of the basic questions—the map's place of origin, the purpose or purposes for which it was made and the circumstances of its production—that have posed such a challenge for scholars. Our preliminary conclusion is that the key to understanding the original primary role of the Gough map lies in its accurate but selective depiction of the settlement geography of fourteenth-century Britain.
Resumo:
Considerable controversy still exists as to whether electric and magnetic fields (MF) at extremely low frequencies are genotoxic to humans. The aim of this study was to test the ability of alternating magnetic fields to induce DNA and chromosomal damage in primary human fibroblasts. Single- and double-strand breaks were quantified using the alkaline comet assay and the gammaH2AX-foci assay, respectively. Chromosomal damage was assayed for unstable aberrations, sister chromatid exchange and micronuclei. Cells were exposed to switching fields - 5min on, 10min off - for 15h over the range 50-1000microT. Exposure to ionizing radiation was used as a positive-effect calibration. In this study two separate MF exposure systems were used. One was based on a custom-built solenoid coil system and the other on a commercial system almost identical to that used in previous studies by the EU REFLEX programme. With neither system could DNA damage or chromosomal damage be detected as a result of exposure of fibroblasts to switching MF. The sensitive gammaH2AX assay could also not detect significant DNA damage in the MF-exposed fibroblasts, although the minimum threshold for this assay was equivalent to an X-ray dose of 0.025Gy. Therefore, with comparable MF parameters employed, this study could not confirm previous studies reporting significant effects for both the alkaline and neutral comet assays and chromosomal aberration induction.
Resumo:
There is an extensive literature on various aspects of segregation in Northern Ireland (NI). However, there are no census-based analyses of population change and residential segregation that cover the entire 1971 – 2001 period using consistent geographical units through time for all NI. This shortcoming is addressed in this paper by an analysis of changes in (ihs1) the spatial distribution of population and (iihs1) residential segregation between 1971 and 2001 using the NI Grid-Square Product comprising data for a set of 1 rm km2 cells that cover all populated areas in NI. The substantive issue of whether NI has become more segregated through time is addressed as are questions about measuring change through time using the census and the importance of spatial scale. One important conclusion is that NI indeed became more residentially segregated between 1971 and 2001, but that residential segregation in 2001 remained approximately at its 1991 level according to most indicators.