971 resultados para Nature in the Bible
Resumo:
This article explores statistical approaches for assessing the relative accuracy of medieval mapping. It focuses on one particular map, the Gough Map of Great Britain. This is an early and remarkable example of a medieval “national” map covering Plantagenet Britain. Conventionally dated to c. 1360, the map shows the position of places in and coastal outline of Great Britain to a considerable degree of spatial accuracy. In this article, aspects of the map's content are subjected to a systematic analysis to identify geographical variations in the map's veracity, or truthfulness. It thus contributes to debates among historical geographers and cartographic historians on the nature of medieval maps and mapping and, in particular, questions of their distortion of geographic space. Based on a newly developed digital version of the Gough Map, several regression-based approaches are used here to explore the degree and nature of spatial distortion in the Gough Map. This demonstrates that not only are there marked variations in the positional accuracy of places shown on the map between regions (i.e., England, Scotland, and Wales), but there are also fine-scale geographical variations in the spatial accuracy of the map within these regions. The article concludes by suggesting that the map was constructed using a range of sources, and that the Gough Map is a composite of multiscale representations of places in Great Britain. The article details a set of approaches that could be transferred to other contexts and add value to historic maps by enhancing understanding of their contents.
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Interspecific interactions are major structuring forces in marine littoral communities; however, it is unclear which of these interactions are exhibited by many key-component species. Gut content analysis showed that the ubiquitous rocky/cobble shore amphipod Echinogammarus marinas, often ascribed as a mesograzer, consumes both algae and macroinvertebrates. Further, laboratory experiments showed that E. marinus is an active predator of such macroinvertebrates, killing and consuming the isopod Jaera nordmanni and the oligochaete Tubificoides benedii. Predatory impacts of E. marinus were not alleviated by the presence of alternative food in the form of alga discs. However, in the presence of prey, consumption of alga by E. marinus was significantly reduced. Further, survival of prey was significantly higher when substrate was provided, but predation remained significant and did not decline with further increases in substrate heterogeneity. We conclude that such amphipods can have pervasive predatory impacts on a range of species, with implications for community structure, diversity and functioning.
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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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We have investigated levels of genetic diversity within and among seven remnant populations of Caesalpinia echinata Lam., an endangered species found as fragmented populations in three major areas around the coastal regions of Brazil. Using amplified fragment length polymorphism (AFLP) genetic markers, we detected levels of within-population genetic diversity ranging from 0.092 to 0.163, with the lowest values generally being found in the smallest populations. Estimates of between-population genetic differentiation were strongly correlated with geographical distance ( r = 0.884, p <0.001), which, along with a neighbour-joining phylogenetic analysis, strongly suggested high levels of genetic isolation by distance. Over half (62%) of the total genetic diversity was partitioned between populations, further highlighting the genetic distinctness of individual populations. Taken together, these results suggest that fragmentation has led to an increase in population differentiation between fragments of C. echinata. These formations will be of great value in the development of conservation plans for species exhibiting high levels of genetic differentiation due to fragmentation, such as indication of conservation unit size, which populations should be chosen as priority in conservation plans and which samples should be introduced in areas with a low number of individuals of brazilwood.
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Density functional theory has been used to study the adsorption of hydroxyl at low and high coverages and also to investigate the nature of the intermediate in the H2O formation reaction on Pt(111). At low coverages [1/9 of a monolayer (ML) to 1/3 ML] OH binds preferentially at bridge and top sites with a chemisorption energy of similar to2.25 eV. At high coverages (1/2 ML to 1 ML) H bonding between adjacent hydroxyls causes: (i) an enhancement in OH chemisorption energy by about 15%; (ii) a strong preference for OH adsorption at top sites; and (iii) the formation of OH networks. The activation energy for the diffusion of isolated OH groups along close packed rows of Pt atoms is 0.1 eV. This low barrier coupled with H bonding between neighboring OH groups indicates that hydroxyls are susceptible to island formation at low coverages. Pure OH as well as coadsorbed OH and H can be ruled out as the observed low temperature intermediate in the water formation reaction. Instead we suggest that the intermediate consists of a mixed OH+H2O overlayer with a macroscopic surface coverage of 3/4 ML in a 2:1 ratio of OH and H2O. (C) 2001 American Institute of Physics.
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The nature of the silver phases of Ag/Al2O3 catalysts (prepared by silver nitrate impregnation followed by calcination) was investigated by X-ray diffractograms (XRD), transmission electron microscopy (TEM) and UV-VIS analyses and related to the activity of the corresponding materials for the oxidation of NO to NO2. The UV-VIS spectrum of the 1.2 wt.% Ag/Al2O3 exhibited essentially one band associated with Ag+ species and the NO2 yields measured over this material were negligible. A 10 wt.% Ag/Al2O3 material showed the presence of oxidic species of silver (as isolated Ag+ cations and silver aluminate), but the UV-VIS data also revealed the presence of some metallic silver. The activity for the NO oxidation to NO2 of this sample was moderate. The same 10% sample either reduced in H-2 or used for the C3H6-selective catalytic reduction (SCR) of NO showed a significantly larger proportion of silver metallic phases and these samples displayed a high activity for the formation of NO2. These data show that the structure and nature of the silver phases of Ag/Al2O3 catalysts can markedly change under reaction feed containing only a fraction of reducing agent (i.e. 500 ppm of propene) in net oxidizing conditions (2.5% O-2). The low activity for N-2 formation during the C3H6-SCR of NO (reported in an earlier study) over the high loading sample can. therefore, he related to the presence of metallic silver. which is yet a good catalyst for NO oxidation to NO2. The reverse observations apply for the oxide species observed over the low loading sample, which is a good SCR catalyst but do not oxidize NO to NO2. (C) 2002 Elsevier Science B.V. All rights reserved.
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This paper is concerned with the production and reproduction of segregation in Northern Ireland and how territoriality has impacted on the Protestant community in Derry/Londonderry. The city was pivotal in the development of the most recent conflict, has a majority Catholic population, sits on a contested border and has attempted to respond to expressions of alienation that have emerged from the Protestant community. The research used multiple methods to understand the nature of alienation and exclusion using secondary data, a quantitative household survey, in-depth interviews and focus
groups. This empirical commitment was important in identifying and unpacking the claims of various stakeholders with an interest in the use and development of the area. It is argued here that a version of Collaborative Planning provides a loosely articulated conceptual and methodological framework for drawing Protestant communities into the wider planning framework for the city. The data, however, suggest that the nature of stakeholders is complex and contradictory, and discursive practice that seeks consensus has limits, especially in validating or legitimating the assertions of self-acclaimed stakeholders. The research shows that the Protestant community had declined and residualised but had little experience of direct conflict with the majority community. Moreover, the Protestant community is now more likely to use the city centre (a predominantly Catholic space) for consumption and work, and its demographic decline has stopped. These findings are important as policy responses and community relations programmes have failed to distinguish between measurable socioeconomic needs and claims concerning ethnic alienation based on emotion and manipulation. Such alienation has tended to bolster single identity communities who have little or no prospect and/or knowledge of the collaborative efforts required to deliver meaningful regeneration. More realistic strategies based on agonism focus attention on power relations and the authenticity of positions adopted by competing interests in land use management and change. The paper concludes by highlighting the need to acknowledge and value contestation but to challenge sectarian discourses represented as legitimate claims about community needs and priorities.
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In his presidential address to the Belfast meeting of the British Association for the Advancement of Science in 1874, John Tyndall launched what David Livingstone has called a ‘frontal assault on teleology and Christian theism’. Using Tyndall's intervention as a starting point, this paper seeks to understand the attitudes of Presbyterians in the north of Ireland to science in the first three-quarters of the nineteenth century. The first section outlines some background, including the attitude of Presbyterians to science in the eighteenth century, the development of educational facilities in Ireland for the training of Presbyterian ministers, and the specific cultural and political circumstances in Ireland that influenced Presbyterian responses to science more generally. The next two sections examine two specific applications by Irish Presbyterians of the term ‘science’: first, the emergence of a distinctive Presbyterian theology of nature and the application of inductive scientific methodology to the study of theology, and second, the Presbyterian conviction that mind had ascendancy over matter which underpinned their commitment to the development of a science of the mind. The final two sections examine, in turn, the relationship between science and an eschatological reading of the signs of the times, and attitudes to Darwinian evolution in the fifteen years between the publication of The Origin of Species in 1859 and Tyndall's speech in 1874.
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We present results of wavepacket simulations for multiphoton ionization in argon. A single active electron model is applied to estimate the single-electron ionization rates and photoelectron energy distributions for lambda = 390 nm light with intensities up to I = 2 x 10(14) W cm(-2). The multiphoton ionization rates are compared with R-matrix Floquet calculations and found to be in very good agreement. The photoelectron energy distribution is used to study the nature of ionization at the higher intensities. Our results are consistent with recent calculations and experiments which show the imprint of the tunnelling process in the multiphoton regime. For few-cycle intense pulses, we find that the strong modulation of intensity and increased bandwidth leads to dynamic mixing of the 3d and 5s resonances.
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This article is based on ethnographic research with young people living in an area of multiple deprivation in the North-east of England. The young people in this study experience many risk factors associated with social exclusion and future offending. Through in-depth examination of crime within the context of their lives, it will be argued that recent theorisations of youth crime and criminal careers do not fully capture the nature of their offending, the contextual circumstances surrounding it and the differential impact of similar risk factors on their lives. The article concludes by suggesting that not only do such theories detract from the situations of poverty and social exclusion in which young people live but that youth policies informed by them potentially add to their experiences of exclusion and marginalisation.
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In this article the authors discuss the usefulness of focus groups for researching sensitive issues using evidence from a study examining the experiences of nurses providing care in the context of the Northern Ireland Troubles. They conducted three group interviews with nurses during which they asked about the issues the nurses face(d) in providing nursing care amid enduring social division. Through a discursive analysis of within-group interaction, they demonstrate how participants employ a range of interpretive resources, the effect of which is to prioritize particular knowledge concerning the nature of nursing care. The identification of such patterned activity highlights the ethnographic value of focus groups to reveal social conventions guiding the production of accounts but also suggests that accounts cannot be divorced from the circumstances of their production. Consequently, the authors argue that focus groups should be considered most useful for illuminating locally sanctioned ways of talking about sensitive issues.
Resumo:
The Galactic Centre is the most active and heavily processed region of the Milky Way, so it can be used as a stringent test for the abundance of deuterium (a sensitive indicator of conditions in the first 1,000 seconds in the life of the Universe). As deuterium is destroyed in stellar interiors, chemical evolution models 1 predict that its Galactic Centre abundance relative to hydrogen is D/H = 5 x 10(-12), unless there is a continuous source of deuterium from relatively primordial (low-metallicity) gas. Here we report the detection of deuterium (in the molecule DCN) in a molecular cloud only 10 parsecs from the Galactic Centre. Our data, when combined with a model of molecular abundances, indicate that D/H = (1.7 +/- 0.3) x 10(-6), five orders of magnitude larger than the predictions of evolutionary models with no continuous source of deuterium. The most probable explanation is recent infall of relatively unprocessed metal-poor gas into the Galactic Centre (at the rate inferred by Wakker(2)). Our measured D/H is nine times less than the local interstellar value, and the lowest D/H observed in the Galaxy. We conclude that the observed Galactic Centre deuterium is cosmological, with an abundance reduced by stellar processing and mixing, and that there is no significant Galactic source of deuterium.
Resumo:
KF, LiF and CsF/A(2)O(3) catalysts with different loadings from 1 to 20 wt% were prepared using aqueous solutions of the alkaline fluoride compounds by wet impregnation of basic mesoporous MSU-type alumina. The catalysts were activated under At at 400 degrees C for 2 h and monitored by in situ XRD measurements. The catalysts were also characterized using several techniques: N-2 adsorption/desorption isotherms at -196 degrees C, FTIR, DR-UV-vis, CO2-TPD, XRD, Al-27 CP/MAS NMR. These characterizations led to the conclusion that the deposition of alkaline fluorides on the alumina surface generates fluoroaluminates and aluminate species. The process is definitivated at 400 degrees C. The fluorine in these structures is less basic than in the parent fluorides, but the oxygen becomes more basic. The catalysts were tested for the transesterification of fatty esters under different experimental conditions using conventional heating, microwave and Ultrasound irradiation. Recycling experiments showed that these catalysts are stable for a limited number of cycles. (C) 2009 Elsevier Inc. All rights reserved.
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Increasingly, mental health social workers in the United Kingdom and elsewhere in the world are employing coercive interventions with clients. This paper explores this trend in the context of community-based settings, using national and international research literature on this subject. It begins with a discussion about the complex, contested nature of ideas on coercion. The authors then explore debates about how coercion is perceived and applied in practice. They choose two forms of coercion*/informal types of leverage, and the legally mandated use of Community Treatment Orders*/to highlight the range of ethical problems and dilemmas that confront practitioners in this field. The authors conclude by developing a tentative, explanatory model to explain how and why mental health social workers should consider a more holistic, situated approach to help deal with ethical concerns about the use of coercion.