929 resultados para history and literature


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(U–Th)/He dating of goethite, when combined with quantification of diffusive 4He loss by the 4He/3He methodology, provides reliable corrected ages for minerals precipitated in weathering profiles. We have combined (U–Th)/He dating of supergene goethite with 40Ar/39Ar dating of supergene manganese oxides to study the weathering history and landscape evolution in the Hamersley Province, northwestern Australia. Incremental heating 40Ar/39Ar analysis of 187 grains of Mn oxides from 65 samples (44 hand specimens) collected from weathering profiles at seven field sites across the Hamersley Province yield precipitation ages ranging from 63.4 ± 0.9 to 1.5 ± 0.2 Ma. These results, combined with previous results of 40Ar/39Ar dating of Mn oxides (Vasconcelos, 1998 Vasconcelos, P.V., 1998. Unpub. report, pp. 1–278.Vasconcelos, 1998 and Cochrane, 2003), reveal a protracted and episodic history of weathering and landscape evolution, which was already ongoing in Late Cretaceous and spans the Palaeogene and Neogene. Seventy-three grains of goethite from 39 samples extracted from 21 hand specimens, collected from the same field sites where the Mn oxides originated, were dated by the (U–Th)/He method. Internally consistent (U–Th)/He ages, which range from 84.3 ± 12.2 to 3.3 ± 0.5 Ma, have been obtained for most samples when corrections are applied for 10% helium diffusive loss. The geochronological results obtained show remarkable similarity in the distribution of ages associated with supergene mineral precipitation. The widespread occurrence of iron oxides such as goethite in soils and weathering profiles and the successful application of (U–Th)/He dating of goethite offers great opportunities for extracting the wealth of palaeoclimatic and palaeoenvironmental information recorded by these profiles on the surface of terrestrial planets such as Earth and Mars.

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Debates about the nature of literacy and literacy practices have been conducted extensively in the last fifteen years or so. The fact that both previous and current British governments have effectively suppressed any real debate makes the publication of this book both timely and important. Here, Urszula Clark stresses the underlying ideological character of such debates and shows that they have deep historical roots. She also makes the point that issues regarding the relationship between language and identity, especially national identity, become sharply focused at times of crisis in that identity. By undertaking a comparison with other major English-speaking countries, most notably Australia, New Zealand and the USA, Clark shows how these times of crisis reverberate around the globe.

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We give a brief exposition of the history of the group rings and some their generalizations. Also we indicate some information of certain problems and results.

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This dissertation is the first systematic study of Armenia’s foreign policy during the post-independence period, between 1991 and 2004. It argues that a small state’s foreign policy is best understood when looking at the regional level. Armenia’s geographic proximity to Iran, Russia and Turkey, places it in an area of heightened geopolitical interest by various great powers. This dissertation explores four sets of relationships with Armenia’s major historical ‘partners’: Russia, Iran, Turkey and the West (Europe and the United States). Each relationship reveals a complex reality of a continuous negotiation between ideas of history, collective memory, nationalism and geopolitics. A detailed study of Armenia’s relations with these powers demonstrates how actors’ relations of amity and enmity are formed to constitute a regional security complex. Turkey represents the ultimate “other”, while both Europe and Iran are seen as ideational “others”, whose role in Armenia’s foreign policy, aside from pragmatic policy considerations, reflects a normative quest. Russia and the United States, on the other hand, represent the powerful structural forces that define the regional security complex, in which Armenia operates. This dissertation argues that although Armenia has been severely constrained in certain foreign policy choices, it was adept at carving a space for action that privileged the issue of Nagorno-Karabakh over other geopolitical imperatives.

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What actors and processes at what levels of analysis and through what mechanisms have pushed Iran's nuclear program (INP) towards being designated as a proliferation threat (securitization)? What actors and processes at what levels of analysis and through what mechanisms have pushed Iran's nuclear program away from being designated as an existential threat (de-securitization)? What has been the overall balance of power and interaction dynamics of these opposing forces over the last half-century and what is their most likely future trajectory? ^ Iran's nuclear story can be told as the unfolding of constant interaction between state and non-state forces of "nuclear securitization" and "nuclear de-securitization." Tracking the crisscrossing interaction between these different securitizing and de-securitizing actors in a historical context constitutes the central task of this project. ^ A careful tracing of "security events" on different analytical levels reveals the broad contours of the evolutionary trajectory of INP and its possible future path(s). Out of this theoretically conscious historical narrative, one can make informed observations about the overall thrust of INP along the securitization - de-securitization continuum. ^ The main contributions of this work are three fold: First, it brings a fresh theoretical perspective on Iran's proliferation behavior by utilizing the "securitization" theory tracing the initial indications of the threat designation of INP all the way back to the mid 1970s. Second, it gives a solid and thematically grounded historical texture to INP by providing an intimate engagement with the persons, processes, and events of Tehran's nuclear pursuit over half a century. Third, it demonstrates how INP has interacted with and even at times transformed the NPT as the keystone of the non-proliferation regime, and how it has affected and injected urgency to the international discourse on nuclear proliferation specifically in the Middle East.^

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Through the administration of questionnaires and interviews in six of London’s secondary schools, this case study seeks to investigate Black Britons’ self-concepts and attitudes toward curricular depictions of continental and diasporan Africans and the extent to which the African Union’s (A.U.) Pan-African outreach agenda may be advanced or challenged.

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Treatment of sensory neuropathies, whether inherited or caused by trauma, the progress of diabetes, or other disease states, are among the most difficult problems in modern clinical practice. Cell therapy to release antinociceptive agents near the injured spinal cord would be the logical next step in the development of treatment modalities. But few clinical trials, especially for chronic pain, have tested the transplant of cells or a cell line to treat human disease. The history of the research and development of useful cell-transplant-based approaches offers an understanding of the advantages and problems associated with these technologies, but as an adjuvant or replacement for current pharmacological treatments, cell therapy is a likely near future clinical tool for improved health care.

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This dissertation is the first systematic study of Armenia’s foreign policy during the post-independence period, between 1991 and 2004. It argues that a small state’s foreign policy is best understood when looking at the regional level. Armenia’s geographic proximity to Iran, Russia and Turkey, places it in an area of heightened geopolitical interest by various great powers. This dissertation explores four sets of relationships with Armenia’s major historical ‘partners’: Russia, Iran, Turkey and the West (Europe and the United States). Each relationship reveals a complex reality of a continuous negotiation between ideas of history, collective memory, nationalism and geopolitics. A detailed study of Armenia’s relations with these powers demonstrates how actors’ relations of amity and enmity are formed to constitute a regional security complex. Turkey represents the ultimate “other”, while both Europe and Iran are seen as ideational “others”, whose role in Armenia’s foreign policy, aside from pragmatic policy considerations, reflects a normative quest. Russia and the United States, on the other hand, represent the powerful structural forces that define the regional security complex, in which Armenia operates. This dissertation argues that although Armenia has been severely constrained in certain foreign policy choices, it was adept at carving a space for action that privileged the issue of Nagorno-Karabakh over other geopolitical imperatives.

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Many fish stocks are currently facing collapse or overexploitation as well as warming environments. During the 1950s and 1960s, haddock supported a substantial fishery in southern Newfoundland waters, specifically Northwest Atlantic Fisheries Organization (NAFO) Divisions 3LNO and Subdivision 3Ps, but abundance has been comparatively low over the last several decades and there has been no significant fishery in either 3LNO or 3Ps since the late-1950s. The decline in the fishery for haddock coincided with a decline in scientific research on haddock with the last significant research on haddock in Newfoundland waters conducted in the 1950s-1960s. Other haddock stocks have shown major life history changes since the 1980s, including decreased size-at-age and age/length at maturity. In contrast to this, Newfoundland haddock have not shown a significant change in growth or maturity through time. Based on analysis of habitat associations, haddock abundance is expected to increase with recent warming trends as the available optimum habitat for haddock will increase.

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© 2015 Royal College of Obstetricians and Gynaecologists. Funded by •Wellbeing of Women/Royal College of Obstetricians and Gynaecologists •Health Research Council of New Zealand

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© 2015 Royal College of Obstetricians and Gynaecologists. Funded by •Wellbeing of Women/Royal College of Obstetricians and Gynaecologists •Health Research Council of New Zealand