Alien species in aquaculture and biodiversity : a paradox in food production

Aquaculture is seen as an alternative to meeting the widening gap in global rising demand and decreasing supply for aquatic food products. Asia, the epicenter of the global aquaculture industry, accounts for over 90% of the global aquaculture production quantity and about 80% of the value. Asian aquaculture, as with global aquaculture, is dependent to a significant extent on alien species, as is the case for all the major food crops and husbanded terrestrial animals. However, voluntary and or accidental introduction of exotic aquatic species (alien species) is known to negatively impact local biodiversity. In this relatively young food production industry, mitigating the dependence on alien species, and thereby minimizing potential negative impacts on biodiversity, is an imperative for a sustainable future. In this context an attempt is made in this synthesis to understand such phenomena, especially with reference to Asian inland finfish, the mainstay of global aquaculture production. It is pointed out that there is potential for aquaculture, which is becoming an increasingly important food production process, not to follow the past path of terrestrial food crops and husbanded animals in regard to their negative influences on biodiversity.

Effects of diets high in whey, soy, red meat and milk protein on body weight maintenance in diet-induced obesity in mice

This study examined the effects of different food sources of protein on energy intake, body weight maintenance, and on the responses of plasma leptin, insulin and adiponectin in chronic high-fat diet-induced obese mice. Obesity was induced in 47 mice with a high-fat diet for 20 weeks. They were divided into five diet groups to test the effects of a higher protein proportion (30% energy), achieved at the expense of carbohydrate. For the next eight weeks, four of the groups were fed diets of chow formulated with whey, soy, red meat or milk while the control group continued on their high-fat diet. The results showed that: (i) increasing the protein : carbohydrate ratio (both at 30% energy) in a high-fat diet did not reduce the level of obesity; (ii) the type of protein added, however, did have a significant effect on the level of obesity attained; (iii) whey protein stabilised weight gain the most, had the strongest satiety effects and also stimulated the highest production of adiponectin; and (iv) whey protein also was associated with the lowest insulin values among all proteins tested. Plasma leptin levels were not affected by any of the diets. Dietary fat remains a potent factor in weight management, but the type and amount of protein may also be important through its effects on food intake. In particular, the apparent decreased appetite associated with increased adiponectin in the whey-based high-protein diet may contribute to stabilised body mass in chronic high-fat diet-induced obesity.

Practising gender : the production of identity by school children

The thesis utilises ‘practice theory’ to argue that the self is not only an effect of social practices but also a technique for action and develops an alternative way of explicating and conceptualising the constitution of the self within the micro-practices of routine, everyday life. This is in contrast to a general tendency within ‘practice theory’, ‘constructionist’ and ‘discursive’ approaches towards a determinist conception of the self. The thesis explores this conceptual framework in fieldwork focussed on formation and production of gender-identity among young school children and offers a new perspective of gender-identity in the classroom. The thesis provides a fourfold contribution: (1) It provides insights into how in the classroom, children take up (conventional) gender differentiated conduct and dispositions in order to forge both their identity and the establishment of a social order based on gender. This gender order is not simply imposed on them by teachers but is actively constructed by the children. The thesis provides insights into how the children in the classroom seize and appropriate the practices of gender for their own ends. These ends, I argue, are the construction of their gender-identity, and the establishment and maintenance of a ‘matrix of intelligibility’. (2) It offers a close-up illustration of how gender construction is negotiated and contested between girls and boys. This is characterised as largely a struggle for enablement — the power to be and to do — rather than as a struggle of one gender over another. (3) It develops an analysis of classrooms as productive sites, as ‘complex strategical situations’ in which the participating agents — the teachers and students—deploy and utilise available resources in their ongoing construction of the world. This suggests that that the social world is not as unitary and totalising as ‘constraint perspectives’ within practice theory often imply. (4) It proposes methodological perspectives and strategies for researching empirically the day-to-day production of gender and for capturing that complex and often elusive process ‘in flight’. It shows the value of an ‘ascending analysis’, one that does not foreclose findings on the basis of a pre-existing theoretical position, and the rich potential of ‘flashpoints’ as a way of illuminating ongoing and often ‘unremarkable’ and therefore unnoticed practices of gender production. The theoretical terrain explored a range of theorists on the self not usually brought together, including Butler, Rose, Foucault, Giddens and Garfinkel and Schatzki. These theorists share in common the perspective that social practices rather than the agent or social totality are the ontological basis of the social world. It is argued that the self is constituted in its enactment and the thesis pursues Foucault’s (2002) question of how the self participates in its own subjectification. The empirical focus of the thesis examined the activities of children at school for insights into how they participated in the making of their gender-identity. The research addressed the questions: (1) To what extent do children construct their gender-identity and what kinds of encouragement do they receive for this? (2) To what extent did the children seem to be appropriating gender practices and inciting the making of gender-identity in the classroom? (3) To what extent can the classroom be viewed as a site of gender contestation and borderwork? Using the concept of ‘flashpoints’, — significant or poignant moments in the classroom — classroom activities were observed to catch gender-identity production ‘in flight’ and to describe how the children seize upon moments to make gender salient. Year Three children in five classrooms in two Victorian schools were observed during English communication and literacy lessons. Individual interviews with teachers in the participating schools and group interviews with the children from the classrooms were undertaken to amplify the observations. Much of the children’s behaviour can be interpreted as their efforts to make gender salient in social interactions. Gender-identity production and gender ‘border work’ (Thorne, 1993) and contestation appeared to be a major activity and preoccupation of the children, even in the face of teacher’s attempts to encourage a gender-neutral environment The children were often more active than the teachers in imposing the ‘gender agenda’ identified by Evans (1988). Overall, this thesis contributes to the development of the theory of subjectivity and identity formation. Social practices are not imposed and individuals seize upon social practices to further their own ends. It is through these routine, everyday activities that social practices are reproduced. The study provides an avenue for understanding the actions of children and the operation of gender power and border work within the classroom.

Effect of dietary arachidonic acid and n-3 polyunsaturated fatty acids on the production of eicosanoids

The major polyunsaturated fatty acid (PUFA) in the western diet is linoleic acid (LA), which is considered to be the major source of tissue arachidonic acid (AA), the principal precursor for the vaso-active eicosanoids via the cyclooxygenase enzymatic pathway. However, dietary AA may contribute significantly to tissue levels of AA in humans, leading to an increase in the production of eicosanoids, particularly the platelet aggregating, vasoconstricting, thromboxane (TXA2), hence increasing thrombosis risk. The aims of this study were to determine the extent to which dietary AA contributed to prostacyclin (PGI2) and TXA2 production in vivo and whether dietary long chain (LC) n-3 PUFA have a modulating influence on the metabolism of AA to these vaso-active eicosanoids. A gas chromatography -mass spectrometry (GCMS) method for urinary PGI2-M determination and a tandem GCMS/MS method for urinary TXA2-M determination were perfected for use within our laboratory (with the assistance of Dr Howard Knapp, University of Iowa and Professor Reinhard Lorenz, Ludwig Maximilian's University, Munich, respectively). An initial animal study compared the in vitro production of PGI2 by aorta segments with the whole body in vivo production of PGI2 in rats fed ethyl arachidonate or the ethyl ester of eicosapentaenoic acid (EPA), at levels many times higher than encountered in human diets. During AA feeding both measures of PGI2 increased, although in vitro TXA2 production was not affected. EPA feeding lowered in vitro TXA2 and in vivo PGI2. Prior to determining the effects of AA and LC n-3 PUFA in humans, a study was carried out to determine the AA and LC n-3 PUFA content of foods and from these, an estimate of the mean daily intake of AA and other LC PUFA. Eggs, organ meats and paté were found to be the richest sources of AA. Of the meat and fish analysed, white meat was found to be relatively rich in AA but poor in LC n-3 PUFA. Lean red meat, particularly kangaroo had similar LC n-3 PUFA and AA content. Fish, although rich in AA, had extremely high levels of LC n-3 PUFA. The calculated mean daily intakes of AA in Australian adults was 130mg (males) and 96mg (females). For total LC n-3 PUFA intake, the mean daily values were 247mg (males) and 197mg (females). Two human pilot studies involving dietary intervention trials examined the effects of dietary AA and AA plus long chain n-3 PUFA on thrombosis risk, gauged by the change in the ratio of PGI2 / TXA2 as well as alterations to other recognised risk factors, such as lipoprotein lipids and platelet aggregation. The desired dietary amounts of AA and LC n-3 PUFA were achieved in the first study by combining food items with known levels of each fatty acid. In the second study, where a diet with approximately equal quantities of AA and LC n-3 PUFA was being examined, kangaroo meat was consumed, following a low-fat vegetarian diet used as a baseline. Diets rich in AA alone (~500mg/day) increased plasma phospholipid (PL) AA levels, PGIi and TXA2 production. When foods containing equal quantities of AA and EPA (∼500mg/day of each) were fed to subjects PGI2 increased, with no change in TXAs production. Low fat vegetarian diets lowered PGI2 production, the level of which was reestablished by an AA rich diet (∼300mg AA/day + ∼260mg/day LC n-3 PUFA) of kangaroo meat. However, TXA2 production was not altered. A final, larger human dietary intervention trial then examined the effects of diets relatively rich in AA alone, AA plus LC n-3 PUFA and LC n-3 PUFA, on the ratio of PGI2/TXA2- The dietary sources of these fatty acids were white meat, red meat and fish, respectively. Each contained a mean level of AA of ∼140mg/day, with varying LC n-3 PUFA levels (59, 161 and 3380mg/day, respectively). Neither meat diet altered PGI2 or TXA2 production significantly, despite increasing serum PL AA levels. The fish diet resulted in a decrease in the serum and platelet PL AA/EPA ratio and TXA2 production, thus increasing the PGI2 / TXA2 ratio. These results would indicate that stores of AA in the body are sufficiently high to have effectively saturated the cyclooxygenase pathway for production of both PGI2 and TXA2, thus making any small change in the plasma level of AA due to 'normal' dietary levels, inconsequential. However, as seen in the rat study and the two pilot studies higher dietary levels of AA can increase both PGI2 and TXA2 production. Increases in platelet levels of EPA and DHA were associated with a decrease in TXA2 production, or the maintenance of a constant TXA2 level, while AA tissue levels and PGI2 production increased. This suggests a possible inhibitory effect of LC n-3 PUFA on the metabolism of AA to TXA2, particularly in platelets. From these short term studies, conducted over 2-3 week periods, it can be concluded that diets rich in lean meats can raise plasma AA levels but do not affect TXA2 or PGI2 production, hence are not pro-thrombotic. Diets rich in long chain n-3 PUFA from fish, raise plasma EPA and DHA levels, lower TXA2 production and are anti-thrombotic. Diets which combine equal quantities of AA and LC n-3 PUFA appear to increase PGI2 production while keeping TXA2 production constant. In order for these LC PUFA to have a significant effect on eicosanoid production the dietary intake of these fatty acids through foods such as red meat or white meat would have to be higher than average current Australian consumption levels.

An aqueous Chlorella extract inhibits IL-5 production by mast cells in vitro and reduces ovalbumin-induced eosinophil infiltration in the airway in mice in vivo

An aqueous extract of the edible microalga, Chlorella pyrenoidosa (CP) (1), has recently been tested for its immunomodulatory effects in a human clinical trial. Here, the CP extract was dialyzed and fractionated using Sephadex G 100 chromatography. The effects of a dialyzed aqueous CP extract, fraction 2, on mast cell mediator release in vitro and ovalbumin-induced allergic airway inflammation in vivo were examined. In vitro, treatment of mouse bone marrow-derived mast cells with 2 for 18 h significantly inhibited antigen (trinitrophenyl-BSA)-induced IL-5 production. In vivo, treatment of mice with 2 during ovalbumin sensitization and stimulation process significantly reduced eosinophil and neutrophil infiltration in the airways. Moreover, fractions obtained by size exclusion chromatography of 2 inhibited IgE-dependent cytokine GM-CSF production from human cord blood-derived mast cells. Taken together, these results suggest that 2 is composed of biopolymers with anti-allergic potential.

Sources of variation contributing to production and quality attributes of Kyrgyz cashmere in Osh and Naryn provinces : implications for industry development

We aimed to quantify the sources of variation contributing to the production and quality of cashmere produced in five districts in Osh and Naryn provinces of Kyrgyzstan. In early spring 2008 mid-side cashmere samples were taken from 719 cashmere adult females, and 41 cashmere adult males and castrates. Samples came from 53 villages and a total of 156 farmers’ flocks. For 91 goats from 33 farmers in 13 villages of two districts that had been sampled earlier, cashmere was combed from the goat at the time of a second visit (end of April 2008) when the cashmere would normally be harvested. Following standard cashmere objective measurement, data were examined using general linear modelling to quantify the effects of potential determinants. The mean fibre diameter (MFD) of cashmere differed between provinces (Osh 15.7 μm, Naryn 16.7 μm; P = 4.4 × 10−20). About 42% of the cashmere was <16 μm, 48% was 16.0–18.0 μm and 9.5% was >18.0 μm. Most of the cashmere samples were coloured (81%), with 63% black and 19% white. The percentage of cashmere samples that were white declined as MFD increased (26% < 14 μm to 11% of >18 μm). The primary determinants of cashmere MFD of individual goats were age of goat (range 1.46 μm, P = 1.8 × 10−12) and farm (range 6.5 μm, P = 1.7 × 10−14). The lesser effects detected for sex (range 0.9 μm, P = 0.026) and colour of cashmere (range 1.8 μm, P = 0.023) were based on small sample sizes and are unreliable. Age of goat had important affects on fibre diameter variation (up to 1.7% in coefficient of variation, P = 5.8 × 10−6) and fibre curvature (2.5–5°/mm, P = 2.1 × 10−4). By far the greatest effect on fibre curvature was cashmere MFD (P = 3.0 × 10−104) with a smaller effect of sex (about 5°/mm, P = 3.0 × 10−6). Village effects were detected on fibre diameter variability (range 4.5% in coefficient of variation, P = 0.027) and fibre curvature (range 15°/mm, P = 1.6 × 10−7). There was a strong negative association between increasing MFD and declining fibre curvature (−5.11 ± 0.181°/mm per 1 μm; P = 7.1 × 10−121; r2 = 0.51). Average combed cashmere weight was 164 g, the clean cashmere content was 0.661 and median clean cashmere production was 110 g per goat (range 60–351 g). Combed cashmere production increased with altitude of the village, probably related to different moulting times as spring temperatures warmed up later in higher altitude villages up to 3200 masl. Measurements of combed cashmere MFD were coarser than the mid-side samples taken earlier in the year. There are farmers and cashmere goats in the sampled districts of Kyrgyzstan which produce the finest qualities of commercial cashmere as the vast majority of cashmere is fine, has low variation in fibre diameter and has fibre crimping (curvature) typical of Chinese and Mongolian cashmere. There is substantial scope to increase the production and commercial value of cashmere produced by Kyrgyz goats. In particular, some villages and farmers need to change their buck selection practices if they wish to produce acceptable cashmere. Farmers should separate their finer and white cashmere prior to sale.

Practice chains of production and consumption : mediatized practices across social fields

The argument developed in this paper is that a focus on practice provides some resolutions to methodological problems facing Bourdieuian scholarship in education. In order to develop Bourdieu's work on practice to account for the interactions between practices, this paper presents a conceptualization of practice as chains of production and consumption. The first part of the paper reviews the account of practice offered by Bourdieu both embedded in practice games and as field effects. The second part of the paper introduces practice chains of production and consumption as a way to conceptualize practice by drawing on a case involving print journalists' involvement with policy makers over the course of an Australian policy review. The final section presents a discussion of this conceptualization and highlights the potential of the concept for further research in understanding the processes of educational policy development.

Using benchmarking to improve the financial and social sustainability of commercial goat meat, cashmere and mohair farms in Australia

Production and financial benchmarking was undertaken with commercially motivated mohair, cashmere and goat meat farmers in Australia. There were large differences in animal and fleece production and financial returns between the best and worst performing farms. Farmers and industry groups reported that the process and results were helpful and resulted in them changing management practices. Benchmarking demonstrated that there is substantial scope to increase productivity and profitability through improved genetic selection and improved management of pastures, breeding flocks and in kid survival and growth.

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.

Fish oil replacement in starter, grow-out, and finishing feeds for farmed aquatic animals

As aquaculture production continues to grow, there will be an increased use of lipid resources (oils and fats) alternative to fish oil for feed production. The potential for the use of these alternatives varies depending on the feeds in which they are included according to the production phase of the animals to which they are being fed. In starter feeds, where rapid growth, high survival, and normal development are critical priorities, there will remain a need for the use of lipid resources high in omega-3 long-chain polyunsaturated fatty acids (n-3 LC-PUFA). Fish in this starter phase have a critical requirement for the n-3 LC-PUFA docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA), and fish oils remain the only cost-effective source of these nutrients in the volumes required. However, the greatest demand for lipids is in those diets for the grow-out phase. Most studies on alternative lipid use with animals in this part of the production phase show positive outcomes, in that there are few studies where all the added fish oil cannot be replaced. There are some species, however, where potential replacement levels are suggested to be more conservative, and a general substitution level in this production phase of 75% has been suggested. One of the key effects noted across the grow-out phase is that all alternatives affect the flesh fatty acid characteristics by reducing the level of n-3 LC-PUFA. This issue has provoked the concept of finisher diets, whereby a high n-3 LC-PUFA content diet is fed in order to restore the desired meat fatty acid profiles. Studies examining this concept have found that the tissue triacylglycerol fatty acids were greatly modified and responded in a simple dilution process to the added oil fatty acid composition, whereas the fatty acids of tissue phospholipids were less influenced by dietary fatty acid makeup.

Fibre production by beef cows

Cattle grow and shed fibre which assists them adapt to seasonal changes in the environment. In the absence of cattle fibre production data for southern Australia, Angus, Hereford, Simmental and Limousin cows and crosses between these breeds grazing perennial pastures at Hamilton, Victoria were sampled in late winter. The fibre-growing area on the sides of cattle was measured, fibre sampled at the mid-side site and the sampling area determined. Fibre was tested for fibre diameter distribution, clean washing yield and fibre length measured. Cows were 3-7 years of age, liveweights were 412-712 kg and the mean fibre-growing area was 2.2 m². This produced an average 682 g of total fibre (range 3461-175 g). The mean fibre diameter of all fibres was 51.7 μm (range 43-62 μm) and 18% of fibres were 36 μm (range 6-39%). The clean washing yield was 92.4% (range 87.4-95.8%). Fibre length averaged 21 mm. Increasing the age, liveweight and condition score of cows and increasing weight of clean fibre were associated with significant increases in mean fibre diameter. Breed of cattle did not affect fibre production (P > 0.1) but did affect mean fibre diameter (P < 0.05). The quantity of fibre production indicates potential for low value textile production. The high level of total fibre production, twice that of an earlier report, and fibre shedding from cattle suggests that white fibre-producing animals such as Merino sheep, Angora and cashmere goats and alpaca should avoid using cattle-handling facilities, particularly in the month before shearing.

Citrus peel influences the production of an extracellular naringinase by Staphylococcus xylosus MAK2 in a stirred tank reactor

Staphylococcus xylosus MAK2, Gram-positive coccus, a nonpathogenic member of the coagulase-negative Staphylococcus family was isolated from soil and used to produce naringinase in a stirred tank reactor. An initial medium at pH 5.5 and a cultivation temperature of 30°C was found to be optimal for enzyme production. The addition of Ca⁺² caused stimulation of enzyme activity. The effect of various physico-chemical parameters, such as pH, temperature, agitation, and inducer concentration was studied. The enzyme production was enhanced by the addition of citrus peel powder (CPP) in the optimized medium. A twofold increase in naringinase production was achieved using different technological combinations. The process optimization using technological combinations allowed rapid optimization of large number of variables, which significantly improved enzyme production in a 5-l reactor in 34 h. An increase in sugar concentration (15 gl^-1) in the fermentation medium further increased naringinase production (8.9 IUml^-1) in the bioreactor. Thus, availability of naringinase renders it attractive for potential biotechnological applications in citrus processing industry.

Schooling and the production of social inequalities : what can and should we be doing?

To speak of an ideal is to lay claim to what ought or should be and to explain 'reality' as deviation. That is, ideals serve to provide direction towards some desired goal as well as judgment about how well a perceived reality approximates that desire. In more recent times, the postmodernist critique has provided its own 'reality check' on modernist ideals, challenging the notion that there is one best way to reach Utopian ends. The emergence of postmodern theories has signalled a general shift in 'the structure of feeling'1 from acquiescence to censure of the universal. But it is not as if there are no postmodern ideals. In these accounts, utopianism is more cogently understood as 'heterotopianisms'. While we are convinced by such critique, that there are diverse goals of value and pathways to reach them, we admit to some uneasiness about a 'postmodern pluralism' in which ideals have die potential to wash away into relativism, where one ideal is as good as the next and ways of achieving them are also equally regarded.

Integrating agriculture and food policy to achieve sustainable peri-urban fruit and vegetable production in Victoria, Australia

Efforts to increase fruit and vegetable consump­tion are a significant aspect of national approaches to preventive health. However, policy frameworks for increasing fruit and vegetable consumption rarely take an integrated food-systems approach that includes a focus on production. In this policy analysis and commentary we examine fruit and vegetable production in peri-urban areas of Melbourne in Victoria, Australia, and highlight the significance of emerging environmental and eco­nomic pressures on fruit and vegetable production. This examination will be of interest to other locations around the world also experiencing pressure on their peri-urban agriculture. These pressures suggest that the availability and afforda­bility of fruit and vegetable supplies cannot be taken for granted, and that future initiatives to increase fruit and vegetable consumption should include a focus on sustainable production. Threats to production that include environmental pressures, together with the loss and cost of peri-urban agri­cultural land and a cost-price squeeze due to rising input costs and low farm-gate prices, act in combi­nation to threaten the viability of the Victorian fruit and vegetable industries. We pro­pose that policy initiatives to increase fruit and vegetable consumption should include measures to address the pressures facing production, and that the most effective policy responses are likely to be integrated approaches that aim to increase fruit and vegetable availability and affordability through innovative solutions to problems of production and distribu­tion. Some brief examples of potential integrated policy solutions are identified to illu­strate the possibilities and stimulate discussion.

Quantifying the potential impacts of increasing agricultural fragmentation on land value

Societal expectations from rural lands have traditionally focused on the production of food and fibre. Yet the perception of rural areas is changing and they are now seen in many instances to be capable of delivering multiple functions or non‐commodity outputs including land conservation and the preservation of biodiversity, contributing to the sustainable management of renewable natural resources and enhancing the socio‐economic viability of many areas . The overall multi‐functionality is constrained or favoured by biophysical and socio‐economic drivers. As these types of drivers vary spatially and temporally, so does the functionality of the landscape and heterogeneous patterns emerge. Associated with multiple functions at a single location are a variety of pressures which can manifest themselves as conflict between interacting land uses. One such conflict in rural zones is that between agricultural use and residential use. Warrnambool City Council (WCC) is a Local Government Area (LGA) in southwest Victoria where the debate surrounding the best use of rural land is currently being debated. In a region where agriculture has historically been the mainstay of the economy there is some resistance to unplanned conversion to residential use. Despite concerns and much strategy being discussed it appears an investigation quantifying the impacts of these conversions is yet to be done. This paper addresses the issue of the allocation of land by using GIS mapping to incorporate economic, social and environmental attributes, and applying a theoretical economic framework for the optimal allocation of land to the comprehensive data set. Marginal values of land for competing purposes are estimated and discussed. The method is relevant for other regions where the rural/residential interface and associated planning decisions are highly topical.