Trophic shifts in three subtropical Australian halfbeaks (Teleostei : Hemiramphidae)

To elucidate the trophic status of hemiramphids, the diets of three species from subtropical south-east Queensland were investigated. All undergo a marked ontogenetic trophic shift from an animal to plant diet, which occurred between 50 and 70mm standard length (L-s) for Arrhamphus sclerolepis krefftii ( freshwater) and between 80 and 110mm L-s for both Hyporhamphus regularis ardelio and H. quoyi ( both marine). After the ontogenetic shift, the diet of A. sclerolepis krefftii is dominated by filamentous algae, whereas the diet of the two marine species is dominated by Zostera capricorni. The two marine species feed mainly during the day, with gut fullness dropping markedly after dusk. Neither showed evidence of a diel trophic shift between herbivory and carnivory that has been reported for other hemiramphids. The lack of diel trophic switching in these subtropical hemiramphids may suggest that latitudinal effects on daylength and/or water temperature may influence the extent to which hemiramphids switch periodically to animal prey from an otherwise essentially herbivorous diet in order to balance their nutrient requirements.

Effect of growing site, moisture stress and seed size on viability and dormancy of Sporobolus pyramidalis (giant rats tail grass) seed

Sporobolus pyramidalis P. Beauv (giant rats tail grass) is a serious agricultural and environmental weed in tropical and subtropical areas of Australia. Infestations of this unpalatable plant reduce the productivity of pastures and the profitability of industries dependent on grazing animals. This paper reports a series of studies undertaken to assist in the development of control strategies for this species. In particular, these studies measured the viability and dormancy status of fresh seed of S. pyramidalis and the decline of dormancy with time. Variability in these characteristics was determined in seeds collected from several sites within south-east Queensland. The effect of moisture availability during the inflorescence and seed production phases on seed viability and dormancy was also determined. The dormancy of freshly collected seed from several sites ranged from 15 to 95%, but decreased to negligible levels after 4-6 months. Seeds that matured under conditions of high moisture availability were initially more dormant than seeds matured where moisture was less readily available. The proportion of viable seeds was significantly lower in smaller than larger seeds even though viability for all seed sizes exceeded 90%. This study has shown that seed of S. pyramidalis generally has high viability with a large proportion of the seed germinable soon after maturity.

Effects of artificial foods on the blood chemistry of the Australian magpie

Bird feeding on residential property is a popular activity throughout Western countries. Advocates insist the practice is beneficial, while opponents maintain that it can result in a wide range of negative outcomes including malnutrition. The biological effects of 'backyard feeding' were studied in Australian magpies Gymnorhina tibicen during the non-breeding season in 1999 in the Greater Brisbane and the Lockyer Valley regions, south-east Queensland, Australia. Six magpie populations were selected and 70 birds were individually tagged for identification. The birds were provided with processed foods, 20-40 g per bird daily. To monitor the effects of the food, blood chemistry and body mass (BM) were used as indices. Significant effects were observed in BM and plasma cholesterol (PC), showing strong sensitivity to food provisioning. Significant effects on PC and uric acid were found only when birds were fed dog sausage. Results suggest that blood PC levels in magpies are readily influenced by, probably, the lipids present in food, and that the type of food can affect blood PC levels. These effects may occur widely among fed magpies if the influence that we demonstrated at plasma level can be generalized. Following the free-ranging study, six magpies were captured and subjected to a 6-day captive experiment to determine whether the selected foods had the potential to alter the birds' blood chemistry. It was found that all of the foods, when provided ad libitum, influence at least two of the three blood parameters (PC and non-esterified fatty acids). Due to its popularity, wildlife feeding will continue. To make wildlife-feeding activities truly sustainable, there is a need for further studies. This study clearly demonstrated that the physiology of wild magpies can be affected by 'backyard feeding'.

A community-based wildlife survey: the knowledge and attitudes of residents of suburban Brisbane, with a focus on bandicoots

Within the expanding city of Brisbane in south-east Queensland, numerous fragments of native and regrowth vegetation are scattered across the largely urbanised landscape. These fragments provide refuge to a great diversity of native wildlife, and, provide residents with the opportunity to experience nature on their doorstep. To assess the diversity and abundance of this wildlife, recent changes in these parameters, and the value of wildlife and bushland fragments to residents of Brisbane, a questionnaire survey was distributed to 300 households each located adjacent to one of 38 urban bushland fragments. A total of 172 surveys (57%) were returned, producing 768 records of 83 fauna species, dominated by birds and mammals; bandicoots were widely reported from the 38 fragments. Several historical records provided evidence of recent local extinctions within fragments, highlighting the continuing declines in various species of native wildlife within Brisbane. Several human-wildlife conflicts were identified, but overall residents were tolerant of such conflicts. Bandicoots were disliked by a small minority (3%) of residents owing to the holes they dig in lawns and gardens in search of food. and their potential as vectors of ticks. Most respondents expressed ail appreciation for the presence of native wildlife (96%) and bushland fragments (97%) in their local area, emphasising the importance of incorporating human dimension values into the management of this urban biodiversity.

Silencing of the ACC synthase gene ACACS2 causes delayed flowering in pineapple [Ananas comosus (L.) Merr.]

Flowering is a crucial developmental stage in the plant life cycle. A number of different factors, from environmental to chemical, can trigger flowering. In pineapple, and other bromeliads, it has been proposed that flowering is triggered by a small burst of ethylene production in the meristem in response to environmental cues. A 1-amino-cyclopropane-1-carboxylate synthase (ACC synthase) gene has been cloned from pineapple (ACACS2), which is induced in the meristem under the same environmental conditions that induce flowering. Two transgenic pineapple lines have been produced containing co-suppression constructs designed to down-regulate the expression of the ACACS2 gene. Northern analysis revealed that the ACACS2 gene was silenced in a number of transgenic plants in both lines. Southern hybridization revealed clear differences in the methylation status of silenced versus non-silenced plants by the inability of a methylation-sensitive enzyme to digest within the ACACS2 DNA extracted from silenced plants, indicating that methylation is the cause of the observed co-suppression of the ACACS2 gene. Flowering characteristics of the transgenic plants were studied under field conditions in South East Queensland, Australia. Flowering dynamics studies revealed significant differences in flowering behaviour, with transgenic plants exhibiting silencing showing a marked delay in flowering when compared with non-silenced transgenic plants and control non-transformed plants. It is argued that the ACACS2 gene is one of the key contributors towards triggering 'natural flowering' in mature pineapples under commercial field conditions.

Using a clinical pathway and education to reduce inappropriate prescribing of enoxaparin in patients with acute coronary syndromes: a controlled study

Aims: To evaluate efficacy of a pathway-based quality improvement intervention on appropriate prescribing of the low molecular weight heparin, enoxaparin, in patients with varying risk categories of acute coronary syndrome (ACS). Methods: Rates of enoxaparin use retrospectively evaluated before and after pathway implementation at an intervention hospital were compared to concurrent control patients at a control hospital; both were community hospitals in south-east Queensland. The study population was a group of randomly selected patients (n = 439) admitted to study hospitals with a discharge diagnosis of chest pain, angina, or myocardial infarction, and stratified into high, intermediate, low-risk ACS or non-cardiac chest pain: 146 intervention patients (September-November 2003), 147 historical controls (August-December 2001) at the intervention hospital; 146 concurrent controls (September-November 2003) at the control hospital. Interventions were active implementation of a user-modified clinical pathway coupled with an iterative education programme to medical staff versus passive distribution of a similar pathway without user modification or targeted education. Outcome measures were rates of appropriate enoxaparin use in high-risk ACS patients and rates of inappropriate use in intermediate and low-risk patients. Results: Appropriate use of enoxaparin in high-risk ACS patients was above 90% in all patient groups. Inappropriate use of enoxaparin was significantly reduced as a result of pathway use in intermediate risk (9% intervention patients vs 75% historical controls vs 45% concurrent controls) and low-risk patients (9% vs 62% vs 41%; P < 0.001 for all comparisons). Pathway use was associated with a 3.5-fold (95% CI: 1.3-9.1; P = 0.012) increase in appropriate use of enoxaparin across all patient groups. Conclusion: Active implementation of an acute chest pain pathway combined with continuous education reduced inappropriate use of enoxaparin in patients presenting with intermediate or low-risk ACS.

Testing alternative models for the conservation of koalas in fragmented rural-urban landscapes

Predicting the various responses of different species to changes in landscape structure is a formidable challenge to landscape ecology. Based on expert knowledge and landscape ecological theory, we develop five competing a priori models for predicting the presence/absence of the Koala (Phascolarctos cinereus) in Noosa Shire, south-east Queensland (Australia). A priori predictions were nested within three levels of ecological organization: in situ (site level) habitat (< 1 ha), patch level (100 ha) and landscape level (100-1000 ha). To test the models, Koala surveys and habitat surveys (n = 245) were conducted across the habitat mosaic. After taking into account tree species preferences, the patch and landscape context, and the neighbourhood effect of adjacent present sites, we applied logistic regression and hierarchical partitioning analyses to rank the alternative models and the explanatory variables. The strongest support was for a multilevel model, with Koala presence best predicted by the proportion of the landscape occupied by high quality habitat, the neighbourhood effect, the mean nearest neighbour distance between forest patches, the density of forest patches and the density of sealed roads. When tested against independent data (n = 105) using a receiver operator characteristic curve, the multilevel model performed moderately well. The study is consistent with recent assertions that habitat loss is the major driver of population decline, however, landscape configuration and roads have an important effect that needs to be incorporated into Koala conservation strategies.

Sustainable Native Floriculture?

The Centre for Native Floriculture (CNF) commenced in May 2003 at The University of Queensland, Gatton. The CNF is a joint initiative with the Queensland State Government, with funding for an initial 3-year period. The phase-out of bush-picking under the South East Queensland Forests Agreement was a catalyst for the Centres establishment. The CNF vision is: ‘to help create an internationally competitive and environmentally sustainable native floriculture industry that provides significant employment opportunities in Queensland’. The Centre is comprised of three research, development and extension programs. The Value Chain Program assists native floriculture industry groups in developing efficient consumer-orientated production, handling and marketing systems for select high potential species. These value chain systems will serve as models for realizing the market potential of and regional fiscal returns on other native ornamental species identified as crop ideotypes that are sought after by end-users (e.g. florists). The Floriculture Program supports the value chain by working to enhance germplasm for the native floriculture industry through selection and breeding, optimize cultivation protocols and overcome any technical barriers that arise. Such barriers include propagation constraints, disease problems and post-harvest limitations. The Capacity Building Program operates to transfer technology and other skills (e.g. value chain management principles) to industry members, train operatives for the industry and promote native floriculture. Conservation of native flora is encouraged through cultivation and community engagement. Protection of biodiversity is advocated via regional production systems that spare natural areas and educate the public as to the biological, floricultural and aesthetic values of native flora. Eco-agricultural tourism focused on wildflowers both in nature and in cultivation is also advocated by the CNF.

Chemical deterrence of a marine cyanobacterium against sympatric and non-sympatric consumers

This study investigates the influence of mesograzer prior exposure to toxic metabolites on palatability of the marine cyanobacterium, Lyngbya majuscula. We examined the palatability of L. majuscula crude extract obtained from a bloom in Moreton Bay, South East Queensland, Australia, containing lyngbyatoxin-a (LTA) and debromoaplysiatoxin (DAT), to two groups: (1) mesograzers of L. majuscula from Guam where LTA and DAT production is rare; and (2) macro- and mesograzers found feeding on L. majuscula blooms in Moreton Bay where LTA and DAT are often prevalent secondary metabolites. Pair-wise feeding assays using artificial diets consisting of Ulva clathrata suspended in agar (control) or coated with Moreton Bay L. majuscula crude extracts (treatment) were used to determine palatability to a variety of consumers. In Guam, the amphipods, Parhyale hawaiensis and Cymadusa imbroglio; the majid crab Menaethius monoceros; and the urchin Echinometra mathaei were significantly deterred by the Moreton Bay crude extract. The sea hares, Stylocheilus striatus, from Guam were stimulated to feed by treatment food whereas S. striatus collected from Moreton Bay showed no discrimination between food types. In Moreton Bay, the cephalaspidean Diniatys dentifer and wild caught rabbitfish Siganus fuscescens were significantly deterred by the crude extract. However, captive-bred S. fuscescens with no known experience with L. majuscula did not clearly discriminate between food choices. Lyngbya majuscula crude extract deters feeding by most mesograzers regardless of prior contact or association with blooms.

Modelling broccoli development, yield and quality

Broccoli is a vegetable crop of increasing importance in Australia, particularly in south-east Queensland and farmers need to maintain a regular supply of good quality broccoli to meet the expanding market. A predictive model of ontogeny, incorporating climatic data including frost risk, would enable farmers to predict harvest maturity date and select appropriate cultivar – sowing date combinations. To develop procedures for predicting ontogeny, yield and quality, field studies using three cultivars, ‘Fiesta’, ‘Greenbelt’ and ‘Marathon’, were sown on eight dates from 11 March to 22 May 1997, and grown under natural and extended (16 h) photoperiods at the University of Queensland, Gatton Campus. Cultivar, rather than the environment, mainly determined head quality attributes of head shape and branching angle. Yield and quality were not influenced by photoperiod. A better understanding of genotype and environmental interactions will help farmers optimise yield and quality, by matching cultivars with time of sowing. The estimated base and optimum temperature for broccoli development were 0°C and 20 °C, respectively, and were consistent across cultivars, but thermal time requirements for phenological intervals were cultivar specific. Differences in thermal time requirement from floral initiation to harvest maturity between cultivars were small and of little importance, but differences in thermal time requirement from emergence to floral initiation were large. Sensitivity to photoperiod and solar radiation was low in the three cultivars used. This research has produced models to assist broccoli farmers in crop scheduling and cultivar selection in south-east Queensland.

The changing nature and role of the head of department

There is little doubt that devolution of responsibility to schools and the growth of school-based management have impacted upon the role and workload of school leaders. Not only Principals have been affected by these changes as Welch (1996) argues that Principals of public secondary schools have passed responsibility down to Deputy-principals and to Heads of Department. As such, the Head of Department role, like other school administration positions, has undergone significant change. Of interest to this paper is the changing role of Heads of Department in secondary schools. This study reports on the findings of semi-structured interviews with eight Heads of Department from four public secondary schools and Principals from each of these schools in South East Queensland. Four years after the first set of interviews, two heads of department were reinterviewed. Both sets of interviews focused upon the role, change, and the importance of leadership. The research generated eight specific themes each of which was considered consistent with the nature of the role in a period of significant cultural change. These were the difference in perceptions regarding the Head of Department role, held by Principals and Heads of Department; Head of Department leadership in terms of a curriculum framed department or whole school leadership; how individuals perceived leadership, and how they learned of leadership; the impact of the changing culture upon the individual Head of Department; the growing influence of situational factors upon the role; the impact of managerialism; the changing nature of a secondary school department; and a growing and more complex workload, and the need for different skills. Furthermore, the findings pointed towards the need for effective change processes and a reconceptualized head of department role. The paper concludes with some implications for the ongoing professional development needs of Heads of Department.

Understanding city fringe gentrification: The role of a potential investment gap

Discussion of gentrification has become ‘balkanised’ into a series of competing and intensely-held positions. The dichotomies are between economic and cultural explanations, supply-side and demand-side explanations and structural Marxist and liberal humanist views. Despite the long academic and policy interest in gentrification there is still no clear definition of what it is and why it occurs. However, almost all previous analyses see gentrification as an inner-city phenomenon and so deal with it within framework of inner-city theory and causation. This paper approaches the debate from a somewhat different position. It argues that gentrification, seen as the replacement of lower status and income households by higher status and income households, can occur outside the inner city. It uses clear cases of gentrification on the urban fringe of metropolitan Brisbane in South East Queensland, to explore mechanisms and explanations. The key to this ‘gentrification by the sea’ is a ‘potential investment gap’ between current and potential future property values, based on increasing demand for a limited locational resource – but instead of this being inner-city properties it is waterside land in a regional facing rapid population increase. The paper also draws attention to the inadequate recognition of the roles of the state and the media in previous analyses of gentrification.

An approach to identifying factors affecting milk protein concentration in dairy cattle

Milk protein production can be influenced by several factors, including environment, disease status, parity, stage of lactation, breed, genetic merit and the nutritional status of the animal (DePeters and Cant 1992). A combination of, or an interaction between, these factors can significantly affect milk protein production. Our study aims to identify the main factors affecting milk protein concentration in dairy cattle in the south-east Queensland region.