5 resultados para Alien

em University of Queensland eSpace - Australia


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In this article, we challenge the hegemony of western science fiction, arguing that western science fiction is particular even as it claims universality. Its view remains based on ideas of the future as forward time. In contrast, in non-western science fiction the future is seen outside linear terms: as cyclical or spiral, or in terms of ancestors. In addition, western science fiction has focused on the good society as created by technological progress, while non-western science fiction and futures thinking has focused on the fantastic, on the spiritual, on the realization of eupsychia-the perfect self. However, most theorists assert that the non-west has no science fiction, ignoring Asian and Chinese science fiction history, and western science fiction continues to 'other' the non-west as well as those on the margins of the west (African-American woman, for example). Nonetheless, while most western science fiction remains trapped in binary opposites-alien/non-alien; masculine/feminine; insider/outsider-writers from the west's margins are creating texts that contradict tradition and modernity, seeking new ways to transcend difference. Given that the imagination of the future creates the reality of tomorrow, creating new science fictions is not just an issue of textual critique but of opening up possibilities for all our futures.

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The increased demographic performance of biological invaders may often depend on their escape from specifically adapted enemies. Here we report that native taxa in colonized regions may swiftly evolve to exploit such emancipated exotic species because of selection caused by invaders. A native Australian true bug has expanded it host range to include a vine imported from tropical America that has become a serious environmental weed. Based on field comparisons and historical museum specimens, we show that over the past 30-40 years, seed feeding soapberry bugs have evolved 5-10% longer mouthparts, better suited to attack the forest-invading balloon vines, which have large fruits. Laboratory experiments show that these differences are genetically based, and result in a near-doubling of the rate at which seeds are attacked. Thus a native biota that initially permits invasion may rapidly respond in ways that ultimately facilitate control.

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The paper examines the ‘endangered ancestress’ theme in Genesis, in which the matriarchs, Sarah and Rebecca, are passed off to alien rulers as the sisters of their respective husbands, in Sarah’s case twice. Rather than viewing these incidents as clumsy duplication, the paper reads them as a literary device in a continuous narrative. The paper argues that when read in this way, these incidents serve to underline the singular status of Sarah in contrast to Rebecca and subsequent matriarchs. Sarah is shown to be the unique foremother of Israel. Alone of all her sex, she represents a pristine new beginning, analogous to human beginnings in Eden.

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Risk assessment systems for introduced species are being developed and applied globally, but methods for rigorously evaluating them are still in their infancy. We explore classification and regression tree models as an alternative to the current Australian Weed Risk Assessment system, and demonstrate how the performance of screening tests for unwanted alien species may be quantitatively compared using receiver operating characteristic (ROC) curve analysis. The optimal classification tree model for predicting weediness included just four out of a possible 44 attributes of introduced plants examined, namely: (i) intentional human dispersal of propagules; (ii) evidence of naturalization beyond native range; (iii) evidence of being a weed elsewhere; and (iv) a high level of domestication. Intentional human dispersal of propagules in combination with evidence of naturalization beyond a plants native range led to the strongest prediction of weediness. A high level of domestication in combination with no evidence of naturalization mitigated the likelihood of an introduced plant becoming a weed resulting from intentional human dispersal of propagules. Unlikely intentional human dispersal of propagules combined with no evidence of being a weed elsewhere led to the lowest predicted probability of weediness. The failure to include intrinsic plant attributes in the model suggests that either these attributes are not useful general predictors of weediness, or data and analysis were inadequate to elucidate the underlying relationship(s). This concurs with the historical pessimism that we will ever be able to accurately predict invasive plants. Given the apparent importance of propagule pressure (the number of individuals of an species released), future attempts at evaluating screening model performance for identifying unwanted plants need to account for propagule pressure when collating and/or analysing datasets. The classification tree had a cross-validated sensitivity of 93.6% and specificity of 36.7%. Based on the area under the ROC curve, the performance of the classification tree in correctly classifying plants as weeds or non-weeds was slightly inferior (Area under ROC curve = 0.83 +/- 0.021 (+/- SE)) to that of the current risk assessment system in use (Area under ROC curve = 0.89 +/- 0.018 (+/- SE)), although requires many fewer questions to be answered.