111,599 research outputs found
Comet and Meteorite Traditions of Aboriginal Australians
Of the hundreds of distinct Aboriginal cultures of Australia, many have oral
traditions rich in descriptions and explanations of comets, meteors,
meteorites, airbursts, impact events, and impact craters. These views generally
attribute these phenomena to spirits, death, and bad omens. There are also many
traditions that describe the formation of meteorite craters as well as impact
events that are not known to Western science.Comment: Encyclopaedia of the History of Science, Technology, and Medicine in
Non-Western Cultures, 2014. Edited by Helaine Selin. Springer Netherland
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Industrialism and the fragmentation of temporal structure
Industrialism's assimilation of the natural world has developed over centuries through complex hierarchies of effects involving ecological, cultural and psychological dimensions. One of the consequences of this assimilation, I argue, is the fragmentation of the temporal structure of the world, and its replacement by a short-term logic that also infects human subjectivity. Because of this fragmentation, the healing of the natural world cannot be realised either simply or directly, and effective action will require us to locate our immediate objectives within a recovered longer-term vision of a healthy natural world
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Depression and the natural world: towards a critical ecology of psychological distress
Researchers have struggled to explain the dramatic increase in diagnoses of âdepressionâ in the industrialised world. This paper argues that psychological distress is likely to arise within an ecological context that is becoming increasingly degraded, and in which the character of selfhood is being redefined to fit an industrialised context. In turn, these redefinitions of selfhood reduce our capacity to address ecological concerns. I argue that it is only possible to recognise the connections between human well-being and ecological health if we identify and challenge the dissociations and repressions on which the âbusiness as usualâ of industrial society depends, and that a more embodied conception of the person is fundamental to this recovery of our wholeness. More specifically, I argue that our current reliance on cognition and our corresponding marginalisation of sensing and feeling, in addition to undermining human well-being, may be ecologically catastrophic
Signatures of hermitian forms and the Knebusch Trace Formula
Signatures of quadratic forms have been generalized to hermitian forms over
algebras with involution. In the literature this is done via Morita theory,
which causes sign ambiguities in certain cases. In this paper, a hermitian
version of the Knebusch Trace Formula is established and used as a main tool to
resolve these ambiguities.
The last page is an erratum for the published version. We inadvertently (I)
gave an incorrect definition of adjoint involutions; (II) omitted dealing with
the case . As , the
omission does not affect our reasoning or our results. For the sake of
completeness we point out where some small changes should be made in the
published version.Comment: This is the final version before publication. The last page is an
updated erratum for the published versio
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Response of rat tracheal epithelium to ozone and oxygen exposure in vitro.
Although ozone-induced epithelial injury in vivo has been morphologically characterized, effects of gaseous oxidants on respiratory epithelium in organ culture, where tissue organization is maintained but systemic influences are eliminated, have not been thoroughly investigated. In this study, we exposed tracheal organ cultures from rats to 95% oxygen and 1 ppm ozone, alone and in combination, to determine (1) whether epithelial responses to ozone similar to those observed in vivo occur in airways separated from systemic physiologic, secretory, and inflammatory reactions; (2) whether concentrations of oxygen sufficient to potentially cause oxidant injury result in morphologic epithelial alterations similar to those that occur in ozone toxicity; and (3) if the combined oxidant insult of oxygen and ozone results in more severe damage to the tracheal epithelium than occurs with ozone in air. Tracheal organ cultures were exposed to filtered air and 5% carbon dioxide; filtered air, 5% carbon dioxide, and 1 ppm ozone; 95% oxygen and 5% carbon dioxide; or 95% oxygen, 5% carbon dioxide, and 1 ppm ozone for 96 hr. Light- and quantitative electron-microscopic evaluation showed that epithelia exposed to 1 ppm ozone in air exhibited loss of ciliated cells and ciliated cell damage. The epithelia exposed to 95% oxygen and 5% carbon dioxide were pseudostratified, columnar, ciliated, and hyperplastic. Epithelia exposed to 95% oxygen plus 1 ppm ozone were stratified and nonciliated or very sparsely ciliated. The predominant cell types in epithelia exposed to oxygen plus ozone were serous cells and metaplastic cells, and focal aggregates of adherent necrotic cells were present. We conclude that there was a synergism between oxygen and ozone exposure leading to enhanced epithelial injury and metaplasia
A method for estimating the extent of denitrification of Arctic polar vortex air from tracer-tracer scatter plots
A method for estimating the extent of denitrification of Arctic polar vortex air is proposed. Previous estimates of denitrification using tracer-tracer scatter plots have not allowed for mixing-induced changes in tracer-tracer relationships in a sufficiently general way. This difficulty is overcome by constructing an artificial "reference tracer'' from a linear combination of other long-lived tracers. The reference tracer is designed so that, as far as possible, it has a linear canonical relationship with NOy in midlatitudes. A linear relationship is unaffected by mixing, so denitrification is apparent as deviations of vortex measurements from the linear midlatitude relationship. The method is first demonstrated using data from a chemical transport model in which no denitrification processes are present. It is then applied to balloon, aircraft and shuttle-borne measurements made before and during the breakdown of the Arctic vortex in 1992-1993 and 1996-1997. In each case the method indicates that little or no denitrification had occurred in any of the vortex air encountered. When the method is applied to the southern hemisphere vortex in 1994, by contrast, denitrified air is clearly seen to be present around 19-23 km in the vortex
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