Production of Australian freshwater crayfish in earthen-based systems using pelleted diets and forage crops as food

Juvenile Cherax destructor (commonly called theyabby) were cultured in earthen-based ponds and tanks for 70–105d, and were fed pellets and/or a forage crop of the perennialwhiteclover, Trifolium repens. Three supplementary feedingstrategies were evaluated. Yabby growth on pellets consistently exceeded (by67–159%) that obtained on clover. Base-line yields for extensiveproduction systems are around 400 kg ha^–1. Thesupplementary addition of T. repens produced yields of 635kg ha^–1 (in ponds) to 1086 kgha^–1 (in tanks). The sequential addition of cut-cloverto tanks stimulated growth to levels approaching those achieved on pellets.Yabbies stocked into ponds at 17 m^–2 and fed 33%protein pellets for 100 d, resulted in a yield of 1117 kgha^–1.Pellet inputs at a rate of 129–249 g m^–2(dry matter) and 38–83 g m^–2 (protein) over70–100 d resulted in acceptable growth and feed utilisationindices. Clover inputs of 534–682 g m–2 (asdry matter) or 84–177 g m^–2 (as protein)produced reasonable growth rates but poor feed utilisation indices. Aconsiderable quantity of the dry matter and protein content of clover waseitherinefficiently utilised or directed into other production pathways. In tanks,clover inputs from 113–296 g m^–2 (drymatter) and 24–54 g m^–2 (protein) weresufficient to maintain high growth rates for 4 weeks, while in ponds, inputs of21 g m^–2 (dry matter) and 4.3 gm^–2 (protein) were sufficient for 3 weeks. During theearly weeks of production no growth advantage was gained by providing pelletstoanimals cultured in forage-based systems. Forage depletion occurred after3–4 weeks and was probably a major growth limiting factor.

Integrating farm production and natural resource management in Tasmania, Australia

This paper reports on the social learning from a project aimed to increase the knowledge and capacity of a group of farmers in Tasmania, Australia, to reduce the impacts of intensive agriculture on soil health and waterways, and to optimise the efficient use of on-farm inputs. The plan-do-check-review cycle adopted in this project required the farmers to assess current management practices, identify where to make changes, implement changes and monitor for improvements. The success of the project was due to careful attention to social processes as well as technical input. The combination of group activities with individual mentoring and one-to-one advice was key to the success of this project in enabling farmers to undertake on-farm action.

There is value in social learning that included developing relationships, using one-to-one contact and group workshops together with expert input when working with farmers to tackle some difficult and complex interrelated natural resource management and production issues. Sufficient time must be allowed for the process of facilitating good practice in natural resource management, particularly when addressing systemic environmental impacts. Practical operational recommendations are presented on communication, feedback, focus of activities and meeting content, as these will be useful to other project officers and facilitators working with farmer groups.

Separating the contributions of hearing, lexical knowledge and speech production to speech perception scores in children with hearing impairments.

Open-set word and sentence speech-perception test scores are commonly used as a measure of hearing abilities in children and adults using cochlear implants and/or hearing aids. These tests are usually presented auditorily with a verbal response. In the case of children, scores are typically lower and more variable than for adults with hearing impairments using similar devices. It is difficult to interpret children's speech-perception scores without considering the effects of lexical knowledge and speech-production abilities on their responses. This study postulated a simple mathematical model to describe the effects of hearing, lexical knowledge, and speech production on the perception test scores for monosyllabic words by children with impaired hearing. Thirty-three primary-school children with impaired hearing, fitted with hearing aids and/or cochlear implants, were evaluated using speech-perception, reading-aloud, speech-production, and language measures. These various measures were incorporated in the mathematical model, which revealed that performance in an open-set word-perception test in the auditory-alone mode is strongly dependent on residual hearing levels, lexical knowledge, and speech-production abilities. Further applications of the model provided an estimate of the effect of each component on the overall speech-perception score for each child.

Development of strategies to increase commercial production of mohair and cashmere in Australia

We aimed to identify impediments to investing into mohair and cashmere production and to suggest programs and strategies to attract investors. Targeted interviews of people focussed on attributes of an investment opportunity. Analysis differentiated views of small and large-scale producers and those not involved in these industries. Potential investors into mohair and cashmere make decisions based on the compatibility of the enterprise to their farm system, the technical, financial and market feasibility of the enterprise and its comparative advantage with other possible courses of action. They are sceptical of information coming from within these industries that is not sufficiently supported by fact. There are many implications from these findings including the need for the industries to: understand the investment decision process; provide objective financial and benchmarking data; make information more accessible; overcome resistance to these industries; and increase the visibility of the industries.

Lithium-functionalised silica nanoparticles for enhanced ionic conductivity in an organic ionic plastic crystal

Addition of silica nanoparticles functionalised with lithium propane sulfonate to the organic ionic plastic crystal N-ethyl-N-methylpyrrolidinium bis(trifluoromethanesulfonyl)amide ([C₂mpyr][NTf₂]) results in a significant increase in ionic conductivity. Analysis of these nanocomposites by impedance spectroscopy, NMR, positron annihilation lifetime spectroscopy (PALS) and Raman spectroscopy suggests that this is the result of higher matrix mobility due to an increase in defect size and concentration. The effect of these functionalised nanoparticles is compared to that previously observed for unfunctionalised nanoparticles in the lithium-doped and pure plastic crystal.

Manipulation of dietary short chain carbohydrates alters the pattern of gas production and genesis of symptoms in irritable bowel syndrome

Background and Aim:  Reduction of short-chain poorly absorbed carbohydrates (FODMAPs) in the diet reduces symptoms of irritable bowel syndrome (IBS). In the present study, we aimed to compare the patterns of breath hydrogen and methane and symptoms produced in response to diets that differed only in FODMAP content.
Methods:  Fifteen healthy subjects and 15 with IBS (Rome III criteria) undertook a single-blind, crossover intervention trial involving consuming provided diets that were either low (9 g/day) or high (50 g/day) in FODMAPs for 2 days. Food and gastrointestinal symptom diaries were kept and breath samples collected hourly over 14 h on day 2 of each diet.
Results:  Higher levels of breath hydrogen were produced over the entire day with the high FODMAP diet for healthy volunteers (181 ± 77 ppm.14 h vs 43 ± 18; mean ± SD P < 0.0001) and patients with IBS (242 ± 79 vs 62 ± 23; P < 0.0001), who had higher levels during each dietary period than the controls (P < 0.05). Breath methane, produced by 10 subjects within each group, was reduced with the high FODMAP intake in healthy subjects (47 ± 29 vs 109 ± 77; P = 0.043), but was not different in patients with IBS (126 ± 153 vs 86 ± 72). Gastrointestinal symptoms and lethargy were significantly induced by the high FODMAP diet in patients with IBS, while only increased flatus production was reported by healthy volunteers.
Conclusions:  Dietary FODMAPs induce prolonged hydrogen production in the intestine that is greater in IBS, influence the amount of methane produced, and induce gastrointestinal and systemic symptoms experienced by patients with IBS. The results offer mechanisms underlying the efficacy of the low FODMAP diet in IBS.

Preparation and characterization of natural rubber/silica nanocomposites using rule of similarity in latex

Rule of similarity and latex compounding techniques were combined for the first time to prepare natural rubber/nanosilica (NR/SiO2) nanocomposite with core-shell nanosilica-poly (methyl methacrylate) (SiO 2-PMMA) particles and PMMA-modified natural rubber matrix (NR-PMMA). The microstructure of SiO2 and nanocomposites with different SiO 2 contents was characterized by fourier transform infrared spectroscopy (FTIR); the morphology of nanocomposites was investigated with scanning electron microscopy (SEM); the tensile strength was characterized by tensile testing machine and the thermal stability of composites was studied by thermal gravimetric analysis. Results showed that PMMA chains have successfully grafted onto the surface of SiO2, and the core-shell SiO 2-PMMA nanoparticles and NR-PMMA latex have been perfectly incorporated. SiO2-PMMA nanoparticles are evenly distributed over the NR matrix with an average size in the range of 60-100 nm at the low content (SiO2? 3 wt%), while aggregations are apparently observed when 5 wt% SiO2 is loaded. In addition, NR/SiO2 composities possess a considerable improvement in ageing resistance compared with the pure NR. The tensile strength of composite increases from 6.99 to 12.72 MPa, reaching the highest value at a 0.5 wt% SiO2 loading, and then the figure decreases gradually because of the aggregation of SiO2 nanoparticles. It is anticipated that the reported process is to provide a simple and economic way for preparing NR composites.

Dietitians' interests in primary food production: opportunities for greater involvement in the promotion of environmental sustainability

Dietitians are food communication professionals. Little is known about their views of food sustainability and security or of their interest in learning more about these issues. Therefore, an online survey of members of the Dietitians’ Association of Australia was conducted during the first half of 2012 about these issues.

Ionic liquid adsorption and nanotribology at the silica-oil interface: hundred-fold dilution in oil lubricates as effectively as the pure ionic liquid

The remarkable physical properties of ionic liquids (ILs) make them potentially excellent lubricants. One of the challenges for using ILs as lubricants is their high cost. In this article, atomic force microscopy (AFM) nanotribology measurements reveal that a 1 mol % solution of IL dissolved in an oil lubricates the silica surface as effectively as the pure IL. The adsorption isotherm shows that the IL surface excess need only be approximately half of the saturation value to prevent surface contact and effectively lubricate the sliding surfaces. Using ILs in this way makes them viable for large-scale applications.