Historical dynamics of the fur seal population : evidence of regulation by man?

The Australian fur seal (Arctocephalus pusillus doriferus) was severely over-exploited in the 18th and 19th centuries and until relatively recently its population had remained steady at well below estimated presealing levels. However, the population is now increasing rapidly (6%–20% per annum) throughout its range and there is a need to understand its dynamics in order to assess the potential extent and impact of interactions with fisheries. Age distribution (n = 156) and pregnancy rate (n = 110) were determined for adult females collected at a breeding colony on Seal Rocks, southeast Australia, in 1971–1972. Mean ± SE and maximum observed ages were 9.37 ± 0.41 and 20 years (n = 1), respectively. A stochastic modelling approach was used to fit an age distribution to the observed age-structure data and calculate rates of recruitment and adult survival. Annual adult female survival and recruitment rates between 1954 and 1971 were 0.478 ± 0.029 (mean ± SE) and 0.121 ± 0.007, respectively, suggesting that the population was experiencing a decline during the 1960s. The pregnancy rate increased from 78% at 3 years of age to an average of 85% between 4–13 years of age before significantly decreasing in older females (the oldest was 19 years of age). There was no significant effect of body mass or condition on the probability of a female being pregnant (P > 0.5 in both cases) and the nutritional burden of lactation did not appear to affect pregnancy rates or gestational performance. These findings suggest that the low survivorship was due to density-independent effects such as mortality resulting from interactions with fishers, which are known to have been common at the time. The recent increase in the population is consistent with anecdotal evidence that such interactions have decreased as fishing practices have changed.

Nasogastric tubes : an historical context

Nurses commonly care for patients with nasogastric tubes. Many authors have addressed the management of nasogastric tubes; however, discussion rarely considers the historical perspective. The purpose of this article is to provide an historical context on nasogastric tubes

Visions of the virtual : the role of computers and artificial intelligence in a selection of Australian young adult fiction

Advances in computer technology over the last twenty years have resulted in a number of different visions of what it means to be real, and of what it means to be human. This paper will explore how computers and artificial intelligence are used as major themes in four Australian novels written for young adults: Gillian Rubinstein’s Space Demons trilogy — comprising Space Demons, Skymaze and Shinkei — and Michael Pryor’s The Mask of Caliban. In so doing, the paper will look at how these texts explore the relationship between increasingly developed technology and visions of a better world. By comparing a series of oppositions that occur in all four books, this paper will look at how the theme of technology is used to privilege particular values and to advocate particular beliefs.

Capitalism's new handmaiden : the biotechnical world negotiated through children's fiction

In an era when the merger between capitalism and science becomes an accepted norm, new questions need to be asked about the ethical implications of scientific practices. One such practice is organ transplantation. However, potent debates surround the just distribution and ethical implications of organ transplantation. This paper examines the ways in which children are socialised through children’s literature to accept or challenge the dominant ideologies underpinning organ transplantation. It argues that how subjectivity is constructed informs understandings of agency, and this in turn can deliver new approaches to concerns about scientific practices.

Estimating expected excess returns using historical and option-implied volatility

We test the relation between expected and realized excess returns for the S&P 500 index from January 1994 through December 2003 using the proportional reward-to-risk measure to estimate expected returns. When risk is measured by historical volatility, we find no relation between expected and realized excess returns. In contrast, when risk is measured by option-implied volatility, we find a positive and significant relation between expected and realized excess returns in the 1994–1998 subperiod. In the 1999–2003 subperiod, the option-implied volatility risk measure yields a positive, but statistically insignificant, risk-return relation. We attribute this performance difference to the fact that, in the 1994–1998 subperiod, return volatility was lower and the average return was much higher than in the 1999–2003 subperiod, thereby increasing the signal-to-noise ratio in the latter subperiod.

The sword and the pen in the pre-modern Arabic heritage : a literacy representation of an important historical relationship

The so-called "literary debate" in Greek, Latin and many Near Eastern
languages is a well-developed genre. In his 1987 article, Geert Jan van Gelder surveyed its background more than adequately, 1 and very few details of that paper need to be repeated here. He assessed thoroughly the historical contribution of numerous poets to the relationship between "the sword and the pen," and also analyzed various aspects of this relationship in a few prose texts.