Nurse plant effects of a dominant shrub (Duma florulenta) on understorey vegetation in a large, semi-arid wetland in relation to flood frequency and drying

 Questions: Do nurse plant interactions significantly influence understorey vegetation diversity in a large, semi-arid, shrub-dominated wetland? How do the modes and net effects of nurse plant interactions vary spatially along a flood frequency gradient, and temporally in response to drying? Location: Narran Lakes Ramsar site, New South Wales, Australia. Methods: Microhabitat characteristics, understorey vegetation and germinable soil seed banks were investigated in shrub and open habitats across a flood frequency gradient in a large, semi-arid wetland dominated by open shrubland under productive conditions following floodwater recession and again following 6 mo of drought. Split-plot ANOVA and multivariate analyses were used to determine the effects of shrubs on microhabitat character, understorey vegetation cover, species diversity, richness and composition and germinable soil seed banks. Results: Microhabitat characteristics, including canopy cover, litter cover and soil character, all differed between shrub and open habitats, especially in the most frequently flooded sites. Under productive conditions following flooding, lignum shrubs suppressed understorey vegetation cover but increased species richness at the site scale across the flood frequency gradient and, in the most frequently flooded sites, supported higher species density at a microhabitat scale. Under dry conditions, lignum shrubs had a positive effect on understorey vegetation cover, species richness and species density across the flood frequency gradient, but particularly in frequently flooded sites. A significant difference in soil seed bank composition between shrub and open habitats was only observed in frequently flooded sites. Conclusions: Nurse plant interactions appear to play an important role in determining understorey vegetation diversity in the lignum shrubland of the Narran Lakes wetland system. The modes and net effects of these nurse plant interactions vary in space and time in relation to flood history and drying. Positive interactions, probably involving microhabitat amelioration, appear to be particularly important to plant diversity and abundance under dry conditions. Under more favourable wetter conditions, lignum shrubs also contribute to understorey vegetation diversity by facilitating the establishment of different species than those dominating open habitats. Our findings have implications for the management of perennial shrubs and hydrological regimes in such wetlands.

Defining diversity and its relation to the local and global: a question of methodology

This paper emerges from research to define the dimensions of diversity and difference within a local Melbourne, Australian school and the requirement to understand these changes in times of increasing globalisation.

Community integration or community exposure? A review and discussion in relation to people with an intellectual disability

Background: This paper reviews the issue of integration as it applies to people with an intellectual disability. A compelling finding is the almost exclusive orientation of the literature to physical integration within the general community of non-disabled people. Moreover, it seems to be generally assumed that the more frequently people experience such integration the better their lives will be. Methods: We question the validity of this assumption on several grounds. It is social, not physical integration, that has a reliable positive influence on well-being. This is an important conclusion as some disabled people find effective social integration with the general community extremely difficult to achieve. Because of this, the consequences of an overly enthusiastic program of integration for such people has more potential to be more stressful than beneficial. Results: We further argue that, as integration is being pursued to benefit the individual, the essential goal of service provision should be to achieve a sense of community connectedness, rather than being concerned with physical integration within the general community.
Conclusion: It is proposed that such connectedness is more likely to be achieved within the community of people with an intellectual disability.

Ambiguities and inconsistencies in relation to the obligations of proxies under corporations law: a model for reform

This article reconsiders the important question which came to light as a result of the controversial 2002 Coles Myer annual general meeting: do directors that are appointed as proxy have an obligation to vote as directed (and indeed should they)? A recent decision of the New South Wales Supreme Court, which was subsequently approved on appeal, stands for the proposition that proxy holders are agents of the shareholders that appointed them. However, currently the Corporations Act only requires a Chairman appointed as proxy to vote as directed — not an ordinary director. This article briefly explains the present state of the law in Australia on this issue, and then explores some interesting recent judicial remarks which may suggest that ordinary directors appointed as proxy must vote as directed in order to satisfy their director’s duties (both common law and statutory) to the company. We finally outline a proposed statutory reform initiative which seeks to remove the present uncertainty in the law by introducing a blanket requirement that all proxy holders must vote as directed.

Empirical evidence from the corporate collapse literature suggesting re-examination of accounting standards in relation to valuation of assets

This paper examines the recent spectacular corporate collapses of Parmalat in Europe, Enron and WorldCom in the USA and HIH in Australia and argues for a re-examination of corporate governance regulations, particularly in relation to accounting standards regarding the valuation of assets. The recommendation that is put forward in this regard is based upon empirical evidence arising from further examination of the empirical results in (Hossari and Rahman, 2004). Specifically, the recommendation is based upon the realization that, among the 48 financial ratios across the 50-plus refereed studies, five financial ratios, all of which contained assets as one of the variables, were a relatively robust indicator of corporate collapse. The five ratios are: Net Income/Total Assets, Current Assets/Current Liabilities, Total Liabilities/Total Assets, Working Capital/Total Assets, and Earnings Before Interest and Taxes/Total Assets. This paper suggests that it's not the failure of the corporate collapse prediction models, rather it's the erosion of the reliability of some key input data, namely assets and the valuation thereof, that is largely responsible for the apparent failure of these models in capturing impending collapses, such as those that we witnessed in the recent past. Such empirical findings support the argument that assets are soft targets for misrepresentation, because of the leeway granted in accounting standards with regards to their valuation.

Gatekeeping or redressing social exclusion : expectations on social work educators in relation to incarcerated students

Until recently, the author was in Scotland, where professional registration in social work extends to students and involves criminal record checks prior to acceptance into a course of study. She is now teaching at Deakin University in Australia, which places a high priority on making higher education available to persons and groups who have traditionally been excluded, both through the provision of courses through off campus (distance education) study mode and an innovative and culturally sensitive mode of provision for indigenous Australians. One result of our attempts to redress social exclusion is that, on occasion, we discover that some of our students are incarcerated. There are important logistical issues which may emerge as a consequence of accepting prisoners into a program of social work education. However, it would seem that the inclusion of prisoners is symbolic of a fundamental difference in philosophy with programmes of social work education in countries where there is a strong expectation that social work educators act as gatekeepers to the profession, especially in respect of students with criminal convictions. This in tum reflects an expectation among social work educators in Australia that it may be more appropriate for professional associations or registration bodies to determine whether or not a graduate with a criminal record is suitable for employment as a professional social worker. In some settings, a prior criminal record is not a barrier to being an effective service provider, as well as international differences in understandings of the social work role and employment
destinations of social work graduates.

Evidence-based paediatric practice and its relation to the Cochrane Collaboration

Focuses on the relation between evidence-based pediatric practice and the Cochrane Collaboration on health care. Formation of the collaboration; Aim of Cochrane Collaboration; Reaction of pediatricians to the collaboration; Ways by which the collaboration ensures its relevance to pediatrics and child health.

The dimensions of self-service technologies and the relation to 'self'

This paper assesses the “behavioural” notion of “self” across the various dimensions of self-service technologies (SSTs). In the context of SSTs, it is acknowledged that the customer role is extended to include that of “service employee”. Therefore, the authors propose the need to explore this new role, from the customer’s perspective, across a diverse range of SSTs. This proposition is supported in that prior research has looked generally across a broad range of SSTs, as opposed to drawing comparisons across the different types of SSTs. In bringing together two classification schemes of SSTs, which does not appear to have been done previously, the authors draw on past research and industry examples to explore the customer experience across different categories of SSTs. It is proposed that the dimensions of SSTs, including level of customer participation as influenced by the purpose of the SST, location of the SST, and type of technology employed, will uniquely influence the notion of “self”, and thus the customer’s SST experience. These propositions have implications for both future research and practice. Future research is needed to study empirically the characteristics of specific SSTs, and compare the many different types of SSTs, and how their unique characteristics influence the customer’s production/consumption experience. When marketers gain a better understanding of the dimensions of individual SSTs, and their influence on the customer, more effective management and use of SSTs will result.

Physical activity and television viewing in relation to risk and undiagnosed abnormal glucose metabolism in adults

OBJECTIVE--The goal of this study was to assess the associations of physical activity time and television (TV) time with risk of "undiagnosed" abnormal glucose metabolism in Australian adults.

RESEARCH DESIGN AND METHODS--This population-based cross-sectional study using a stratified cluster design involving 42 randomly selected Census Collector Districts across Australia included 8,299 adults aged 25 years or older who were free from new type 2 diabetes and self-reported ischemic disease and did not take lipid lowering or antihypertensive drugs. Abnormal glucose metabolism (impaired fasting glycetnia [IFG], impaired glucose tolerance [IGT], or new type 2 diabetes) was based on an oral glucose tolerance test Self reported physical activity time and TV time (previous week) were assessed using interviewer administered questionnaires.

RESULTS--Alter adjustment for known confounders and TV time, the odds ratio (OR) of having abnormal glucose metabolism was 0.62 (95% CI 0.41-0.96) in men and 0.71 (0.501.00) in women for those engaged in physical activity [greater than or equal to] 2.5 h/week compared with those who were sedentary (0 h/week). The ORs of having abnormal glucose metabolism were 1.16 (0.791.70) in men and 1.49 (1.12-1.99) in women who watched TV > 14 h/week compared with those who watched [less than or equal to] 7.0 h/week. Higher TV viewing (> 14 h/week) was also associated with an increased risk of new type 2 diabetes in men and women and IGT in women compared with those watching < 14 h/week. Total physical activity of [greater than or equal to] 2.5 h/week was associated with a reduced risk of IFG, IGT, and new type 2 diabetes in both sexes: however, only the association with IGT in women was statistically significant.

CONCLUSIONS--These findings suggest a protective effect of physical activity and a deleterious effect of TV time on the risk of abnormal glucose metabolism in adults. Population strategies to reduce risk of abnormal glucose metabolism should focus on reducing sedentary behaviors such as TV time, as well as increasing physical activity.

Distribution of an alien aquatic snail in relation to flow variability, human activities and water quality

1. Disturbance and anthropogenic land use changes are usually considered to be key factors facilitating biological invasions. However, specific comparisons of invasion success between sites affected to different degrees by these factors are rare.

2. In this study we related the large-scale distribution of the invading New Zealand mud snail (Potamopyrgus antipodarum) in southern Victorian streams, Australia, to anthropogenic land use, flow variability, water quality and distance from the site to the sea along the stream channel.

3. The presence of P. antipodarum was positively related to an index of flow-driven disturbance, the coefficient of variability of mean daily flows for the year prior to the study.

4. Furthermore, we found that the invader was more likely to occur at sites with multiple land uses in the catchment, in the forms of grazing, forestry and anthropogenic developments (e.g. towns and dams), compared with sites with low-impact activities in the catchment. However, this relationship was confounded by a higher likelihood of finding this snail in lowland sites close to the sea.

5. We conclude that P. antipodarum could potentially be found worldwide at sites with similar ecological characteristics. We hypothesise that its success as an invader may be related to an ability to quickly re-colonise denuded areas and that population abundances may respond to increased food resources. Disturbances could facilitate this invader by creating spaces for colonisation (e.g. a possible consequence of floods) or changing resource levels (e.g. increased nutrient levels in streams with intense human land use in their catchments).

Whale distribution in relation to prey abundance and oceanographic processes in the shelf waters of the Western Antarctic Peninsula

The Western Antarctic Peninsula (WAP) is a biologically rich area supporting large standing stocks of krill and top predators (including whales, seals and seabirds). Physical forcing greatly affects productivity, recruitment, survival and distribution of krill in this area. In turn, such interactions are likely to affect the distribution of baleen whales. The Southern Ocean GLOBEC research program aims to explore the relationships and interactions between the environment, krill and predators around Marguerite Bay (WAP) in autumn 2001 and 2002. Bathymetric and environmental variables including acoustic backscattering as an indicator of prey abundance were used to model whale distribution patterns. We used an iterative approach employing (1) classification and regression tree (CART) models to identify oceanographic and ecological variables contributing to variability in humpback Megaptera novaeangliae and minke Balaenoptera acutorstrata whale distribution, and (2) generalized additive models (GAMs) to elucidate functional ecological relationships between these variables and whale distribution. The CART models indicated that the cetacean distribution was tightly coupled with zooplankton acoustic volume backscatter in the upper (25 to 100 m), and middle (100 to 300 m) portions of the water column. Whale distribution was also related to distance from the ice edge and bathymetric slope. The GAMs indicated a persistent, strong, positive relationship between increasing zooplankton volume and whale relative abundance. Furthermore, there was a lower limit for averaged acoustic volume backscatter of zooplankton below which the relationship between whales and prey was not significant. The GAMs also supported an annual relationship between whale distribution, distance from the ice edge and bathymetric slope, suggesting that these are important features for aggregating prey. Our results demonstrate that during the 2 yr study, whales were consistently and predictably associated with the distribution of zooplankton. Thus, humpback and minke whales may be able to locate physical features and oceanographic processes that enhance prey aggregation.