Home-range use by the brush-tailed phascogale (phascogale tapoatafa) (marsupialia) in High-quality, spatially limited habitat

Nine phascogales (7 females, 2 males) were radio-tracked between March and July 1999 to investigate the spatial organisation of this species in spatially limited habitat near Euroa, Victoria. In this area, approximately 3.6% of the original woodland vegetation remains after 150 years of agricultural clearing. Most wooded habitat is confined to narrow linear strips along roads and streams. However, these remnants are on fertile soils and, because they have not experienced intensive harvesting, the density of large old trees is over 10 times that found in nearby State Forests and Parks. Female phascogales were monitored for 13–38 days over periods of 5–15 weeks. The size of home ranges of females was 2.3–8.0 ha, and averaged 5.0 ha. This value is one-eighth the mean home-range size previously recorded for the species in contiguous forest in Victoria. All individuals used multiple nest trees, with nests generally located in trees >80 cm diameter at breast height. Although fragmented and spatially limited, the stands of large old trees on productive soils near Euroa provide a network of well connected, high-quality habitat for phascogales. The relatively dense population of phascogales in these remnants suggests that prior to agricultural clearing and timber harvesting, phascogales may have been much more common in Victoria than at present.

Are age-related variations in breeding performance greatest when food availability is limited?

Age-related improvements in reproductive performance in seabirds have been well documented, and may be explained by improvements in foraging efficiency or increased experience and reproductive effort with age. The interactive effects of parental age and food supply on reproductive performance, however, remain poorly understood. A widespread mass mortality of pilchards Sardinops sagax in southern Australian waters in 1998 provided a unique opportunity to investigate the effects of a sudden reduction in the availability of amajor prey species on Australasian gannets Morus serrator, an important local marine predator. Age-related differences in the breeding performance of gannets were evident in 1 year of reduced pilchard availability; when food was not limited, both young and experienced parents were equally capable of rearing chicks and had similar levels of breeding success. These data clearly demonstrate the interactive effects of parental age and food supply on breeding performance and suggest that such differences only become apparent when conditions become more stressful.

No outbreeding depression at a regional scale for a habitat-forming intertidal alga with limited dispersal

Hormosira banksii is distributed throughout southern Australasia, but dispersal of propagules is thought to be limited. In the present study, the hypothesis that outbreeding depression occurs in H. banksii was tested by assessing fertilisation success and early development of embryos in crosses between populations at local to regional spatial scales. Hierarchical experiments were conducted at three spatial scales with nesting present within each scale: small scale (within a rocky shore population), intermediate scale (regions separated by 70 km) and large scale (450-km separation between two states: Victoria and Tasmania). In each experiment, eggs and sperm were crossed within and between each population located in the spatial scale of interest. There were no consistent patterns of variable fertilisation success and subsequent development within a population or at different spatial scales. It was concluded that outbreeding depression is not detected in analyses of fertilisation success or early development processes in H. banksii. The results suggest one of the following to be likely: (1) H. banksii is capable of longer distance dispersal than previously considered, thus maintaining gene flow between distant populations, (2) gene flow is restricted by limited dispersal, but populations have not been isolated for a sufficient length of time to cause genetic divergence or (3) outbreeding depression is manifested as effects on later life-history stages.

Technology and marginalization: a case study of the limited adoption of the intranet at a state-owned organisation in rural Australia

Taking a critical theory approach and the pluralist view of technology, this paper examines the problems in organizational communication that arose due to the implementation of a limited intranet electronic mail system as the main channel of communication between a rural stateowned organization and its city-based Head Office, installed at the sole discretion of the latter.
The intranet was provided only to the administration division and managers of some units due to financial constraints. This required others to receive information carried via the intranet through a gatekeeper who due to information and work overload, failed to disseminate the information effectively and efficiently. Using a combination of qualitative data collection methods, this study found that the intranet had marginalized those without access to it and reinforced the privileged position of those already with higher status within the organization, contrary to the utopian predictions
of new technologies as leading to social equality.

Sexual conflict and polyspermy under sperm-limited conditions : in situ evidence from field simulations with the free-spawning marine echinoid Evechinus chloroticus

For free‐spawning organisms that release gametes into the sea, sperm limitation (too few sperm to fertilize all eggs) is a major factor limiting reproductive success. Given such circumstances, the presence of several mechanisms to prevent polyspermy (too many sperm) may seem paradoxical; however, a growing body of data suggests that natural fertilization levels, though variable, can routinely be high. Under such conditions, polyspermy is much more likely. The tension between sperm limitation and polyspermy represents sexual conflict because males, in competing to fertilize as many eggs as possible, can impose lethal costs on eggs if multiple sperm gain entry. Here we present data for a marine invertebrate indicating high levels of polyspermy under sperm‐limited conditions. When the sea urchin Evechinus chloroticus was induced to spawn in situ, mean rates of polyspermy were 17.3% ±3.4%, and polyspermy was recorded at rates as high as 62.7%. Polyspermy was nearly always present, even when fertilization rates were <50%, confirming predictions that it should be present under sperm‐limited conditions. Both sperm limitation and polyspermy imposed substantial reproductive costs, and we conclude that both sexual conflict related to polyspermy and sperm limitation have been simultaneous strong selective forces shaping the evolution of reproductive traits in the sea.

Stress-shielding as a cause of insertional tendinopathy: the operative technique of limited adductor tenotomy supports this theory

The aetiology of tendinopathy is poorly understood. A new hypothesis proposed argues that tendinopathy may not be purely a tensile injury, rather that altered mechanics such as compression or stress-shielding may be important. Both tendon compression and a decrease in tendon load (stress-shielding) will induce change in a tendon similar to that seen in an insertional tendinopathy.

Stress-shielding as a cause of tendinopathy is supported by the clinical success of operative release of adductor longus. This surgery releases the superficial section of the normal adductor longus tendon at a point distal to the insertion. This may have the effect of transferring stress from the superficial section of the tendon to the stress-shielded deeper portion, and the induction of normal loads in both the deeper and superficial portions of the tendon may assist in tendon recovery. This interesting hypothesis and clinical intervention require further investigation

Limited Liability Act of 1855

Examines the Limited Liability Act 1855 and highlights its significance in the formation of the modern company's legal framework. Looks at the background to the Act, which was repealed after a few months and incorporated in the Joint Stock Companies Act 1856 in an amended form. Considers the Act's legacy in extending the general principle of limited liability for corporate debts to shareholders of registered companies, including its implications in allowing a greater diversification of shareholders.

Frequency of migraine and the risk of cardiovascular disease for women : limited evidence of an association

Evaluation of: Kurth T, Schurks M, Logroscino G et al. Migraine frequency and risk of cardiovascular disease in women. Neurology 73, 581–588 (2009). There is substantial evidence that migraine with aura (MA) is associated with ischemic stroke and myocardial infarction in women. The mechanisms of this association are poorly understood. Analysis of data from the Women’s Health Study, from 27,798 women over 45 years of age who were initially free of cardiovascular disease, found that women with baseline MA at a frequency of less than monthly had increased risk of major cardiovascular disease (HR: 2.28; 95% CI: 1.70–3.07) relative to women without migraine, and those who reported MA with a frequency of more than weekly had more than four-times the risk of ischemic stroke (HR: 4.25; 95% CI: 1.36–13.29) compared with those without migraine. Low numbers of outcome events in each of the frequency categories and lack of information on migraine frequency during follow-up limit the interpretation of these findings, but they suggest that frequency of migraine may be a moderating factor in the link between MA and cardiovascular disease.

Building realities less limited than their own : young people practising same sex attraction on the internet

The internet has met with mixed community reactions, especially when the focus is on young people's internet use. There are those who fear that the internet will introduce undesirable people and information into the home, leaving the young vulnerable and exploited. Alternatively, there are others who argue that the exclusion of young people from the internet is one of many examples of the diminishing public space that is made available to young people in this post-modern world. In this article we focus on the internet use of one ‘space deprived’ group of marginalized young people, those who are same-sex attracted. Regardless of some important changes in Australian culture and law, these young people's opportunities to openly live their sexual difference remain restricted. In this article we are interested in exploring the role of the internet as a space in which some important sexuality work can be done. What we found was that the internet was providing young people with the space to practise six different aspects of their sexual lives namely identity, friendship, coming out, intimate relationships, sex and community.