200 resultados para Irish Studies


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This paper investigates evidence for palaeoclimatic changes during the period ca. 1500-500 cal. yr BC through peat humification studies on seven Irish ombrotrophic bogs. The sites are well-correlated by the identification of three mid-first millennium BC tephras, which enable the humification records at specific points in time to be directly compared. Phases of temporarily increased wetness are suggested at ca. 1300-1250 cal. yr BC, ca. 1150-1050 cal. yr BC, ca. 940 cal. yr BC and ca. 740 cal. yr BC. The last of these is confirmed to be synchronous at five sites, suggesting external forcing on a regional scale. The timing of this wet-shift is constrained by two closely dated tephras and is demonstrated to be distinct from the widely reported changes to cooler/wetter conditions associated with a solar minimum at 850-760 cal. yr BC, at which time the Irish sites appear instead to experience drier conditions. The results suggest the possibility of either non-uniform responses to solar forcing in northwest Europe at this time, or the existence of unrelated climate events in the early first millennium BC. The findings caution against the correlation of loosely dated palaeoclimate data if the effects of forcing mechanisms are to be understood.

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This paper examines the importance of British contributions to the success of the Irish hospitals sweepstake. In its early years, up to three-quarters of these tickets were sold in Britain, bringing millions of pounds into Ireland annually to improve and expand the state's hospitals. The vast amount of money leaving Britain in this way angered the British government and forced it to introduce new legislation to curtail the activities of the Irish sweep. The paper will highlight the extent to which the success of the sweepstake depended on the market for tickets in Britain; the threat to the sweep's survival posed by the restriction of its activities in Britain after 1935; the role of the sweepstake controversy in exacerbating further already strained relations between Britain and the Irish Free State in the 1930s; how the success of the sweep raised the issue of legalising a British lottery; and the eventual decline of the sweepstake as a force in British gambling in the post-war years.

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Populations of Gammarus duebeni celticus, previously the only amphipod species resident in the rivers of the Lough Neagh catchment, N. Ireland, have been subjected to invasion by G. pulex from the British mainland. Numerous previous studies have investigated the potential behavioural mechanisms, principally differential mutual predation, underlying the replacement of G. d. celticus by G. pulex in Irish waters, and the mutually exclusive distributions of these species in Britain and mainland Europe. However, the relative degree of influence of abiotic versus biotic factors in structuring these amphipod communities remains unresolved. This study used principal component analysis (PCA) to distinguish physico-chemical parameters that have significant roles in determining the current distribution of G. pulex relative to G. d. celticus in L. Neagh rivers. We show that the original domination of rivers by the native G. d, celticus has changed radically, with many sites in several rivers containing either both species or only G. pulex. G. pulex was more abundant than the G. d. celticus in sites with low dissolved oxygen levels. This was reflected in the macroinvertebrate assemblages associated with G. pulex in these sites, which tended to be those tolerant of low biological water quality. The present study thus emphasizes the importance of the habitat template, particularly water quality, for Gammarus spp. interactions. If rivers become increasingly stressed by organic pollution, it is probable the range expansion of G. pulex will continue. Because these two species are not ecological equivalents, the outcomes of G. pulex incursions into G. d. celticus sites may ultimately depend on the prevailing physico-chemical regimes in each site.

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Bees are believed to be in decline across many of the world's ecosystems. Recent studies on British bumblebees proposed alternative theories to explain declines. One study suggested that greater dietary specialization among the rarer bumblebee species makes them more susceptible to decline. A second study disputed this theory and found that declines in British bumblebees were correlated with the size of species' European ranges, leading to the suggestion that climate and habitat specialization may be better indicators of the risk of decline. Here we use a new and independent dataset based on Irish bumblebees to test the generality of these theories. We found that most of the same bumblebee species are declining across the British Isles, but that, within Ireland, a simple food-plant specialization model is inadequate to explain these declines. Furthermore, we found no evidence of a relationship between declines in Irish bumblebees and the size of species' European ranges. However, we demonstrate that the late emerging species have declined in Ireland (and in Britain), and that these species show a statistically significant westward shift to the extremity of their range, probably as a result of changing land use. Irish data support the finding that rare and declining bumblebees are later nesting species, associated with open grassy habitats. We suggest that the widespread replacement of hay with silage in the agricultural landscape, which results in earlier and more frequent mowing and a reduction in late summer wildflowers, has played a major role in bumblebee declines. (C) 2006 Elsevier Ltd. All rights reserved.

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This article examines the processes and outcomes of community involvement in six Irish urban regeneration case studies, three in Dublin and three in Belfast. The findings are part of a wider study using a Complex Adaptive Systems perspective to analyse public sector decision making. Key points included: (1) the community ‘vision’ of the regeneration as an emergent property, which converged towards the vision held by the implementing agencies in the four most successful programmes; and (2) the identification of three features that contribute to non-linear (unpredictable) behaviour: a history of community involvement; the availability of resources; and the intervention of key individuals at crisis points.

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Peat has been widely used as a low cost adsorbent to remove a variety of materials including organic compounds and heavy metals from water. Various functional groups in lignin allow such compounds to bind on active sites of peat. The adsorption of Cu2+ and Ni2+ from aqueous solutions on Irish peat moss was studied both as a pure ion and from their binary mixtures under both equilibrium and dynamic conditions in the concentration range of 5–100 mg/L. The pH of the solutions containing either Cu2+ or Ni2+ was varied over a range of 2–8. The adsorption of Cu2+ and Ni+2 on peat was found to be pH dependent. The adsorption data could be fitted to a two-site Langmuir adsorption isotherm and the maximum adsorption capacity of peat was determined to be 17.6 mg/g for Cu2+ and 14.5 mg/g for Ni2+ at 298 K when the initial concentration for both Cu2+ and Ni2+ was 100 mg/L, and the pH of the solution was 4.0 and 4.5, respectively. Column studies were conducted to generate breakthrough data for both pure component and binary mixtures of copper and nickel. Desorption experiments showed that 2 mM EDTA solution could be used to remove all of the adsorbed copper and nickel from the bed.