997 resultados para Holden, W. W. (William Woods), 1818-1892.


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The Australian Alfred Walter Campbell (1868-1937) is remembered as one of the two chief pioneers of the study of the cytoarchitectonics of the primate cerebral cortex. He had worked in Britain carrying out neuroanatomical and neuropathological research for almost two decades before his famous monograph on Histological Studies on the Localisation of Cerebral Function appeared in 1905. In that year he returned to his native Australia and practiced for over 30 years in Sydney as a neurologist rather than a neuropathologist, publishing mainly clinical material though he was involved in the investigation of the epidemic of Australian X disease, a viral encephalitis. His abrupt change in both the nature and the location of his career at a time when he was well established in Britain appears to have been a consequence of his marriage and the need to provide for a family. His simultaneous apparent abandonment of research seems not to have really been the case. As judged from the contents of a paper presented to a local medical congress in Sydney in 1911, it appears that, in Australia, Campbell did carry out a major comparative anatomical and histological investigation of the possibility of localization of function in the cerebellar cortex. He never published this work in detail. His investigation let him to conclude that no such localization of function existed, a view contrary to the then topical interpretation of Bolk (1906), but one in accordance with Gordon Holmes' views a decade later. Campbell's circumstances in Sydney, his extremely reticent nature and the essentially negative outcome of his investigation probably explain his failure to make his study more widely known.

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The short-lived Hf-182-W-182-isotope system is an ideal clock to trace core formation and accretion processes of planets. Planetary accretion and metal/silicate fractionation chronologies are calculated relative to the chondritic Hf-182-W-182-isotope evolution. Here, we report new high-precision W-isotope data for the carbonaceous chondrite Allende that are much less radiogenic than previously reported and are in good agreement with published internal Hf-W chronometry of enstatite chondrites. If the W-isotope composition of terrestrial rocks, representing the bulk silicate Earth, is homogeneous and 2.24 epsilon(182W) units more radiogenic than that of the bulk Earth, metal/silicate differentiation of the Earth occurred very early. The new W-isotope data constrain the mean time of terrestrial core formation to 34 million years after the start of solar system accretion. Early terrestrial core formation implies rapid terrestrial accretion, thus permitting formation of the Moon by giant impact while Hf-182 was still alive. This could explain why lunar W-isotopes are more radiogenic than the terrestrial value. Copyright (C) 2002 Elsevier Science Ltd.

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The subject of this study was a typical, if in some respects well qualified, U.S. ambassadorial appointee for his time, the early twentieth century: an attorney, judge, and politician who served competently in his one diplomatic assignment, in Berlin, before returning to private life.—Ed.

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Este trabalho objetivou testar a resistência natural da madeira de Eucalyptus grandis de quatro diferentes idades (10, 14, 20 e 25 anos) ao ataque de cupins de madeira seca. As amostras foram retiradas da prancha diametral, na região próxima ao cerne mais externo, em número de seis unidades por tora, de cada uma das 16 árvores (quatro de cada idade). Cada par de amostras foi colocado em contato com 40 indivíduos, da espécie Cryptotermes brevis (cupim de madeira seca), avaliando-se cada par comparativamente com corpos-de-prova de madeira altamente suscetível ao ataque de cupins, no caso a madeira de Pinus elliottii, sob idênticas condições laboratoriais, mediante observações em intervalos periódicos. Ao término do ensaio foram registrados a porcentagem de cupins mortos e o número de furos, além do desgaste produzido por esses insetos. Verificou-se que a madeira de 10 anos foi a mais severamente atacada, com desgaste semelhante ao da testemunha. As madeiras de 14, 20 e 25 anos não diferiram estatisticamente entre si, quanto à resistência natural ao ataque de cupim de madeira seca, todas classificadas como de desgaste acentuado. A madeira de todas as idades mostrou-se altamente suscetível ao ataque de cupins, revelando a baixa resistência natural da espécie.

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A notícia da morte de James W. Carey, aos 71 anos, no passado dia 23 de Maio de 2006 deixou um profundo vazio na comunidade de estudiosos da comunicação e do jornalismo. Considerado nos EUA como um dos mais influentes pensadores do último terço do século XX nesta área de estudo, embora pouco conhecido na Europa, Carey foi e será uma referência para quem, nos tempos actuais, insiste, mesmo que romanticamente, em pensar a comunicação como ritual cultural de cooperação e democracia.

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Pure tungsten and tantalum plates and tungsten-tantalum composites produced via mechanical alloying and spark plasma sintering were bombarded with He+ and D+ energetic ion beams and deuterium plasmas. The aim of this experiment is to study the effects caused by individual helium and deuterium exposures and to evidence that the modifications induced in the composites at different irradiation energies could be followed by irradiating the pristine constituent elements under the same experimental conditions, which is relevant considering the development of tailored composites for fusion applications. Higher D retentions, especially in tungsten, and superficial blistering are observed in both components after helium exposure. The blistering is magnified in the tantalum phase of composites due to its higher ductility and to water vapour production under deuterium irradiation. At lower irradiation energies the induced effects are minor. After plasma exposure, the presence of tantalum does not increase the D content in the composites. (C) 2013 Elsevier B.V. All rights reserved.

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This paper suggests that the thought of the North-American critical theorist James W. Carey provides a relevant perspective on communication and technology. Having as background American social pragmatism and progressive thinkers of the beginning of the 20th century (as Dewey, Mead, Cooley, and Park), Carey built a perspective that brought together the political economy of Harold A. Innis, the social criticism of David Riesman and Charles W. Mills and incorporated Marxist topics such as commodification and sociocultural domination. The main goal of this paper is to explore the connection established by Carey between modern technological communication and what he called the “transmissive model”, a model which not only reduces the symbolic process of communication to instrumentalization and to information delivery, but also politically converges with capitalism as well as power, control and expansionist goals. Conceiving communication as a process that creates symbolic and cultural systems, in which and through which social life takes place, Carey gives equal emphasis to the incorporation processes of communication.If symbolic forms and culture are ways of conditioning action, they are also influenced by technological and economic materializations of symbolic systems, and by other conditioning structures. In Carey’s view, communication is never a disembodied force; rather, it is a set of practices in which co-exist conceptions, techniques and social relations. These practices configure reality or, alternatively, can refute, transform and celebrate it. Exhibiting sensitiveness favourable to the historical understanding of communication, media and information technologies, one of the issues Carey explored most was the history of the telegraph as an harbinger of the Internet, of its problems and contradictions. For Carey, Internet was seen as the contemporary heir of the communications revolution triggered by the prototype of transmission technologies, namely the telegraph in the 19th century. In the telegraph Carey saw the prototype of many subsequent commercial empires based on science and technology, a pioneer model for complex business management; an example of conflict of interest for the control over patents; an inducer of changes both in language and in structures of knowledge; and a promoter of a futurist and utopian thought of information technologies. After a brief approach to Carey’s communication theory, this paper focuses on his seminal essay "Technology and ideology. The case of the telegraph", bearing in mind the prospect of the communication revolution introduced by Internet. We maintain that this essay has seminal relevance for critically studying the information society. Our reading of it highlights the reach, as well as the problems, of an approach which conceives the innovation of the telegraph as a metaphor for all innovations, announcing the modern stage of history and determining to this day the major lines of development in modern communication systems.

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In the history of modern communication, after the development of the printing press, the telegraph unleashed a revolution in communications. Today, Internet is in many ways its heir. Reflections on the telegraph may open up perspectives concerning tendencies, possibilities and pitfalls of the Internet. The telegraph has been well explored in important literature on communication and media which tends to emphasize the history of this technology, its social context and institutional meaning [e.g. Robert L. Thompson, 1947, Tom Standage, 2007 [1998]. James W. Carey, the North- American critical cultural studies' mentor, in his essay "Technology and Ideology. The Case of the Telegraph" (2009 [1983]), suggests a distinctive approach. In the telegraph, Carey sees the prototype of many subsequent commercial empires based on science and technology, a pioneer model for complex business management; an example of interest struggle for the patents control; an inductor of changes both in language and in structures of knowledge; and a promoter of a futurist and utopian thought of information technologies. Having in mind a revolution in communications promoted by the Internet, this paper revisits this seminal essay to explore its great attainment, as well as the problems of this kind of approach which conceives the innovation of the telegraph as a metaphor for all the innovations announcing the modern stage of history and determining still today the major lines of development in modern communication systems.

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N.º4, p.263-267