702 research outputs found

    Catering for cultural and linguistic diversity: using teacher created information texts

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    Teachers in the Pacific region have often signalled the need for more locally produced information texts in both the vernacular and English, to engage their readers with local content and to support literacy development across the curriculum. The Information Text Awareness Project (ITAP), initially informed by the work of Nea Stewart-Dore, has provided a means to address this need through supporting local teachers to write their own information texts. This article reports on the impact of an ITAP workshop carried out in Nadi, Fiji, in 2012. Nine teacher volunteers from the project trialled the use of the texts in their classrooms with positive results in relation to student learning and belief in themselves as writers

    Live Transport of Crustaceans in Air - Prolonging the Survival of Crabs

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    We studied the live transport of crustaceans in air, using the spanner crab Ranina ranina as an example, and developed guidelines for handling live spanner crabs which we presented to an industry workshop. Our findings were also of general relevance to the live shipment of other oceanic crab species. The spanner crab fishery has burgeoned over the last couple of years through interest in the live market. The choice of spanner crabs as a topic of study was therefore timely . The handling practices used on boats in this fishery, (storing crab s out of water), were appropriate for handling "live" crabs destined for cooking but we found that more careful handling was required for the live export market. While spanner crabs appeared to tolerate being stored in air, our studies showed that this tolerance was misleading. The crabs stressed quickly when they arrived on deck and became quiescent . Their blood pH fell rapidly, a symptom called acidosis . Quiescence was their only means of dealing with acidosis. In practical terms, any time that a spanner crab was out of water was too long. Spanner crabs are stored in air twice after harvest, first while on the boat and again when actually exported . The conditions experienced by the crabs stored in air at ambient temperature on boats were much worse than those of crabs cooled for export. At the very least, the crabs should be cooled down or sprayed with cold seawater when stored in air on boats. The best way to store crabs on boats would be submerged in live wells but there are problems with this because the unrestrained crabs can injure each other. We also tested other methods of alleviating stress. Spanner crabs cannot buffer low pH in the blood, unlike many other commercially harvested crustaceans. We sought to correct this using a dip treatment . However, this did not improve their survival. For an animal that cannot correct acidosis, spanner crabs survive for an extraordinary period in air. The stressed crabs may linger on because they "shut down" and keep the acidosis from reaching fatal levels. Using the results of our research, we presented guidelines for handling spanner crabs at an industry workshop on December 9-1Oth 1993. This workshop attracted favourable comment from the industry and copies of several papers were published in the May edition of Queensland Fisherman. We concluded that the way the crabs are currently being handled on boats is too stressful. Physiological studies show that spanner crabs, like other oceanic crabs, are not well equipped to survive in air . Yet even if you store them cold on the boat they still die after a few days in tanks on shore. This mortality is an impediment to the maturity of the industry. The crabs may be succumbing to bacterial infections caused by injury and we recommend that their claws are immobilised by banding after capture

    Streptophage-mediated control of off-flavour taint producing streptomycetes isolated from barramundi ponds

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    Off-flavour taint of aquaculture products is a global issue reducing consumer confidence in the farmed produce as they are taken up via the gills of fish, and deposited in the lipids of the animal. If the fish are not purged, resulting undesirable muddy earthy flavour taint can be tasted by consumers. These undesirable flavour and odour is caused by the terpenoid compounds namely geosmin and 2-methylisoborneol, produced as secondary metabolites by certain bacteria including the cyanobacteria and actinomycetes. Current strategies to remediate the problem rely on treating the symptoms not the cause and involve the use of time consuming purging methods and costly chemicals. Biological control using bacteriophages, specific to the problem causing bacteria, offers a natural alternative to chemical control, which might reduce further complications of copper based algaecides and its subsequent implications on water quality. In an adaptation of such biological control approach streptomycetes isolated from barramundi ponds were tested for their susceptibility to streptophages to understand whether host destruction via phage lysis would subsequently eliminate off-flavour taint productions by these isolates. Following the determination of the streptophage susceptibility of the isolates one of the most odourous streptomycete species (USC-14510) was selected to be tested further using different pond simulations resembling real-life applications. Geosmin was tested as the indicator of off-flavour taint production and as it has been previously reported that the cyanobacteria-actinomycete interactions occurring in ponds result in even greater levels of geosmin and 2-methylisoborneol, the geosmin levels for the isolate in the presence of cyanobacteria and streptophages were also tested. Findings indicated that the highly odourous Streptomyces species (USC-14510) once infected with streptophages, can lose its capacity to produce off-flavour taints. Pond simulation studies also revealed geosmin production was significantly reduced when streptophages were introduced into the pond water where streptomycete species were grown. The bacteriophage control method developed in the presented study might again confirm significant potential for the bacteriophage-mediated remediation strategy to be adapted by the aquaculture industry

    Floating photovoltaics could mitigate climate change impacts on water body temperature and stratification

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    Floating solar photovoltaics, or floatovoltaics (FPV), are a relatively new form of renewable energy, currently experiencing rapid growth in deployment. FPV decarbonises the energy supply while reducing land-use pressures, offers higher electricity generating efficiencies compared to ground-based systems and reduces water body evaporation. However, the effects on lake temperature and stratification of FPV both sheltering the water’s surface from the wind and limiting the solar radiation reaching the water column are unresolved, despite temperature and stratification being key drivers of the ecosystem response to FPV deployment. These unresolved impacts present a barrier to further deployment, with water body managers concerned of any deleterious effects. To overcome this knowledge gap, here the effects of FPV-induced changes in wind speed and solar radiation on lake thermal structure were modelled utilising the one-dimensional process-based MyLake model. To resolve the effect of FPV arrays of different sizes and designs, observed wind speed and solar radiation were scaled using a factorial approach from 0% to 100% in 1% intervals. The simulations returned a highly non-linear response, dependent on system design and coverage. The responses could be either positive or negative, and were often highly variable, although, most commonly, water temperatures reduce, stratification shortens and mixed depths shallow. Modifications to the thermal dynamics of the water body may subsequently drastically alter biogeochemical processes, with fundamental implications for ecosystem service provision and water treatment costs. The extreme nature of response for particular wind speed and solar radiation combinations results in impacts that could be comparable to, or more significant than, climate change. As such, depending on how they are used, FPV have the potential to mitigate some of the impacts of climate change on water bodies and could be a useful tool for water body managers in dealing with changes to water quality, or, conversely, they could induce deleterious impacts on standing water ecosystems. These simulations provide a starting point to inform the design of future systems that maximise ecosystem service and environmental co-benefits from this growing water body change of use
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