235 research outputs found

    The social practice of sustainable agriculture under audit discipline: initial insights from the ARGOS project in New Zealand

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    One of the most interesting recent developments in global agri‐food systems has been the rapid emergence and elaboration of market audit systems claiming environmental qualities or sustainability. In New Zealand, as a strongly export‐oriented, high‐value food producer, these environmental market audit systems have emerged as an important pathway for producers to potentially move towards more sustainable production. There have, however, been only sporadic and fractured attempts to study the emerging social practice of sustainable agriculture – particularly in terms of the emergence of new audit disciplines in farming. The ARGOS project in New Zealand was established in 2003 as a longitudinal matched panel study of over 100 farms and orchards using different market audit systems (e.g., organic, integrated or GLOBALG.A.P.). This article reports on the results of social research into the social practice of sustainable agriculture in farm households within the ARGOS projects between 2003‐2009. Results drawn from multiple social research instruments deployed over six years provide an unparalleled level of empirical data on the social practice of sustainable agriculture under audit disciplines. Using 12 criteria identified in prior literature as contributing a significant social dynamic around sustainable agriculture practices in other contexts, the analysis demonstrated that 9 of these 12 dimensions did demonstrate differences in social practices emerging between (or co‐constituting) organic, integrated, or conventional audit disciplines. These differences clustered into three main areas: 1) social and learning/knowledge networks and expertise, 2) key elements of farmer subjectivity – particularly in relation to subjective positioning towards the environment and nature, and 3) the role and importance of environmental dynamics within farm management practices and systems. The findings of the project provide a strong challenge to some older framings of the social practice of sustainable agriculture: particularly those that rely on paradigm‐driven evaluation of social motivations, strong determinism of sustainable practice driven by coherent farmer identity, or deploying overly categorical interpretations of what it means to be ‘organic’ or ‘conventional’. The complex patterning of the ARGOS data can only be understood if the social practice of organic, integrated or (even more loosely) conventional production is understood as being co‐produced by four dynamics: subjectivity/identity, audit disciplines, industry cultures/structure and time. This reframing of how we might research the social practice of sustainable agriculture opens up important new opportunities for understanding the emergence and impact of new audit disciplines in agriculture

    Australia's coastal fisheries and farmed seafood: An ecological basis for determining sustainability

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    In response to consumer concerns about the sustainability of Australian-sourced seafood we derive a set of criteria within an explicit decision-process that can be used to determine whether locally farmed and wild-caught Australian seafood products meet standards of ecological sustainability and Ecologically Sustainable Development. These criteria substantially address the ecological deficiencies we identified in other systems commonly used for assessing seafood sustainability. The criteria address the issues that are relevant to local seafood production, and are populated with indicators (metrics) and benchmarks relevant to the Australian context. The indicators establish performance thresholds drawn from public domain data about the products, including observed empirical data and proxies, and include default decisions to be applied in the absence of adequate information. This decision structure is set within a peer-reviewed expert jury decision-making process. The criteria, decision process and decision outcomes from assessment of a number of pilot products were tested in a real seafood market (Melbourne), where we found a high level of producer, reseller and consumer acceptance of the judgements and ratings. The use of ecologically-derived standards results in several outcomes that differ from those of other seafood assessment systems, especially those assessments more focused on production standards, such as government, industry and NGO-supported programs, popularly used in Australia and worldwide. We conclude that despite high levels of uncertainty surrounding many of the population parameters, ecological patterns and processes, empirical cost-effective proxies can be used to reasonably estimate a form of sustainability that matches consumer interests/expectations for production of fresh local seafood. Despite the plethora of industry and government programs, there remains a significant but presently unmet consumer demand for ecologically-based, technically robust, independently derived, and readily available information about the local sustainability attributes of Australian wild-caught and farmed fresh seafood

    Alginate inhibits iron absorption from ferrous gluconate in a randomized controlled trial and reduces iron uptake into Caco-2 cells

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    Previous in vitro results indicated that alginate beads might be a useful vehicle for food iron fortification. A human study was undertaken to test the hypothesis that alginate enhances iron absorption. A randomised, single blinded, cross-over trial was carried out in which iron absorption was measured from serum iron appearance after a test meal. Overnight-fasted volunteers (n=15) were given a test meal of 200g cola-flavoured jelly plus 21 mg iron as ferrous gluconate, either in alginate beads mixed into the jelly or in a capsule. Iron absorption was lower from the alginate beads than from ferrous gluconate (8.5% and 12.6% respectively, p=0.003). Sub-group B (n=9) consumed the test meals together with 600 mg calcium to determine whether alginate modified the inhibitory effect of calcium. Calcium reduced iron absorption from ferrous gluconate by 51%, from 11.5% to 5.6% (p=0.014), and from alginate beads by 37%, from 8.3% to 5.2% (p=0.009). In vitro studies using Caco-2 cells were designed to explore the reasons for the difference between the previous in vitro findings and the human study; confirmed the inhibitory effect of alginate. Beads similar to those used in the human study were subjected to simulated gastrointestinal digestion, with and without cola jelly, and the digestate applied to Caco-2 cells. Both alginate and cola jelly significantly reduced iron uptake into the cells, by 34% (p=0.009) and 35% (p=0.003) respectively. The combination of cola jelly and calcium produced a very low ferritin response, 16.5% (p<0.001) of that observed with ferrous gluconate alone. The results of these studies demonstrate that alginate beads are not a useful delivery system for soluble salts of iron for the purpose of food fortification

    Estimation of Dietary Iron Bioavailability from Food Iron Intake and Iron Status

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    Currently there are no satisfactory methods for estimating dietary iron absorption (bioavailability) at a population level, but this is essential for deriving dietary reference values using the factorial approach. The aim of this work was to develop a novel approach for estimating dietary iron absorption using a population sample from a sub-section of the UK National Diet and Nutrition Survey (NDNS). Data were analyzed in 873 subjects from the 2000–2001 adult cohort of the NDNS, for whom both dietary intake data and hematological measures (hemoglobin and serum ferritin (SF) concentrations) were available. There were 495 men aged 19–64 y (mean age 42.7±12.1 y) and 378 pre-menopausal women (mean age 35.7±8.2 y). Individual dietary iron requirements were estimated using the Institute of Medicine calculations. A full probability approach was then applied to estimate the prevalence of dietary intakes that were insufficient to meet the needs of the men and women separately, based on their estimated daily iron intake and a series of absorption values ranging from 1–40%. The prevalence of SF concentrations below selected cut-off values (indicating that absorption was not high enough to maintain iron stores) was derived from individual SF concentrations. An estimate of dietary iron absorption required to maintain specified SF values was then calculated by matching the observed prevalence of insufficiency with the prevalence predicted for the series of absorption estimates. Mean daily dietary iron intakes were 13.5 mg for men and 9.8 mg for women. Mean calculated dietary absorption was 8% in men (50th percentile for SF 85 µg/L) and 17% in women (50th percentile for SF 38 µg/L). At a ferritin level of 45 µg/L estimated absorption was similar in men (14%) and women (13%). This new method can be used to calculate dietary iron absorption at a population level using data describing total iron intake and SF concentration

    Bootstrapping Q Methodology to Improve the Understanding of Human Perspectives.

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    Q is a semi-qualitative methodology to identify typologies of perspectives. It is appropriate to address questions concerning diverse viewpoints, plurality of discourses, or participation processes across disciplines. Perspectives are interpreted based on rankings of a set of statements. These rankings are analysed using multivariate data reduction techniques in order to find similarities between respondents. Discussing the analytical process and looking for progress in Q methodology is becoming increasingly relevant. While its use is growing in social, health and environmental studies, the analytical process has received little attention in the last decades and it has not benefited from recent statistical and computational advances. Specifically, the standard procedure provides overall and arguably simplistic variability measures for perspectives and none of these measures are associated to individual statements, on which the interpretation is based. This paper presents an innovative approach of bootstrapping Q to obtain additional and more detailed measures of variability, which helps researchers understand better their data and the perspectives therein. This approach provides measures of variability that are specific to each statement and perspective, and additional measures that indicate the degree of certainty with which each respondent relates to each perspective. This supplementary information may add or subtract strength to particular arguments used to describe the perspectives. We illustrate and show the usefulness of this approach with an empirical example. The paper provides full details for other researchers to implement the bootstrap in Q studies with any data collection design

    Changing from a Western to a Mediterranean-style diet does not affect iron or selenium status:Results of the New Dietary Strategies Addressing the Specific Needs of the Elderly Population for Healthy Aging in Europe (NU-AGE) 1-year randomized clinical trial in elderly Europeans

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    Background: Mediterranean diets limit red meat consumption and increase intakes of high-phytate foods, a combination that could reduce iron status. Conversely, higher intakes of fish, a good source of selenium, could increase selenium status. Objectives: A 1-y randomized controlled trial [New Dietary Strategies Addressing the Specific Needs of the Elderly Population for Healthy Aging in Europe (NU-AGE)] was carried out in older Europeans to investigate the effects of consuming a Mediterraneanstyle diet on indices of inflammation and changes in nutritional status. Methods: Selenium and iron intakes and status biomarkers were measured at baseline and after 1 y in 1294 people aged 65–79 y from 5 European countries (France, Italy, the Netherlands, Poland, and the United Kingdom) who had been randomly allocated either to a Mediterranean-style diet or to remain on their habitual, Western diet. Results: Estimated selenium intakes increased significantly with the intervention group (P < 0.01), but were not accompanied by changes in serum selenium concentrations. Iron intakes also increased (P < 0.001), but there was no change in iron status. However, when stratified by study center, there were positive effects of the intervention on iron status for serum ferritin for participants in Italy (P = 0.04) and France (P = 0.04) and on soluble transferrin receptor (sTfR) for participants in Poland (P < 0.01). Meat intake decreased and fish intake increased to a greater degree in the intervention group, relative to the controls (P < 0.01 for both), but the overall effects of the intervention on meat and fish intakes were mainly driven by data from Poland and France. Changes in serum selenium in the intervention group were associated with greater changes in serum ferritin (P = 0.01) and body iron (P = 0.01), but not sTfR (P = 0.73); there were no study center × selenium status interactions for the iron biomarkers. Conclusions: Consuming a Mediterranean-style diet for 1 y had no overall effect on iron or selenium status, although there were positive effects on biomarkers of iron status in some countries. The NU-AGE trial was registered at clinicaltrials.gov as NCT01754012. Am J Clin Nutr 2019;00:1–12

    How organic farmers view their own practice: results from the Czech Republic

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    This paper addresses the development of organic agriculture in the Czech Republic, which is seen as a success story among post-communist countries. The relatively short history of organic farming and specific contextual factors raises questions about the nature and meaning of Czech organic farming. The goal of this study was to find out how farmers view their own practice, interpret its symbolic value, and construct its content. This empirical study uses Q methodology aimed at the identification of the collectively-shared perspectives belonging engaged actors. Data were gathered through semi-standardized interviews with Czech farmers registered in official organic scheme. The analysis emphasized three components, which are considered as three distinct perspectives possessed by organic farmers; that is, (1) organic farming as a way of life, (2) as an occupation, and (3) as a production of food of an alternative quality compared to conventional food. Each viewpoint entails a different understanding of what organic farming means; each then—when considered together—comprises the meaning of organic agriculture in the Czech Republic. The presented classification of the farmers holding the viewpoints contributes to the ongoing theoretical discussion regarding the nature of the current organic sector, its development and potential conventionalization

    Safety of Ecklonia cava phlorotannins as a novel food pursuant to Regulation (EC) No 258/97

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    Following a request from the European Commission, the EFSA Panelon Dietetic Products, Nutrition and Allergies (NDA) was asked to deliver a scientific opinion on the safety of Ecklonia cava phlorotannins (marketed as SeaPolynol) as a novel food submitted pursuant to Regulation (EC) No258/97. The novel food is a phlorotannin-rich alcohol extract of Ecklonia cava, which is an edible marine brown alga species. The information provided on the composition, the specifications, the production process and the batch-to-batch variability of the novel food is sufficient and does not raise safety concerns. The intention is to market the novel food as a food supplement for healthy individuals over the age of 12years. A subchronic repeated dose oral toxicity study in rodents tested the novel food at daily doses of 0, 375, 750 and 1,500mg/kg body weight (bw). The Panelconsiders the mid-dose as the no-observed-adverse-effect-level (NOAEL) of the study. Taking into account this NOAEL of 750mg/kg bw per day and by applying an uncertainty factor of 200, the Panelconsiders an intake level of 3.75mg/kg bw per day as safe. The Panelconcludes that the novel food, Ecklonia cava phlorotannins, is safe for the use in food supplements at a maximum daily intake level of 163mg/day for adolescents from 12 to 14years of age, 230mg/day for adolescents above 14years of age and 263mg/day for adults. (C) 2017 European Food Safety Authority. EFSA Journal published by John Wiley and Sons Ltd on behalf of European Food Safety Authority

    Safety of 1-methylnicotinamide chloride (1-MNA) as a novel food pursuant to Regulation (EC) No258/97

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    Following a request from the European Commission, the EFSA Panelon Dietetic Products, Nutrition and Allergies (NDA) was asked to deliver an opinion on 1-methylnicotinamide chloride (1-MNA) as a novel food (NF) ingredient submitted pursuant to Regulation (EC) No258/97 of the European Parliament and of the Council, taking into account the comments and objections of a scientific nature raised by Member States. 1-MNA is a substance present naturally in the human body as a normal downstream product of niacin metabolism. The Panelconsiders that the information provided on the composition, the specification and the batch-to-batch variability of the NF is sufficient. The applicant intends to use 1-MNA in food supplements and proposes a maximum intake of 58mg/day. 1-MNA is not genotoxic. In a subchronic rat study, epithelium degeneration of the non-glandular stomach was observed at all dose levels with increasing frequency. The Panelnotes that the human stomach does not have non-glandular epithelium and considers this finding is toxicologically not relevant for humans. At doses of 500 and 1,000mg/kg body weight (bw), changes of the urine pH, that did not reverse in the recovery period, were reported. As adversity of this finding cannot be ruled out, the Panelselected 250mg/kg bw in this rat study as the reference point. The Margin of Exposure to humans weighing 70kg and consuming 58mg would be about 300. The Panelnotes the upper level for nicotinamide, i.e. 900mg/day for adults. Taking into account that 1-MNA is a main metabolite from nicotinamide, the Panelconsiders that it is unlikely that an intake of 58mg 1-MNA from food supplements would result in adverse health outcomes in humans. The Panelconcludes that the NF, 1-MNA, is safe under the proposed uses and use levels. (C) 2017 European Food Safety Authority. EFSA Journal published by John Wiley and Sons Ltd on behalf of European Food Safety Authority

    Multiphase turbulence in bubbly flows: RANS simulations

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    The ability of a two-fluid Eulerian–Eulerian computational multiphase fluid dynamic model to predict bubbly air–water flows is studied. Upward and downward pipe flows are considered and a database of 19 experiments from 6 different literature sources is used to assess the accuracy of the model, with the aim of evaluating our ability to predict these kinds of flows and to contribute to ongoing efforts to develop more advanced simulation tools. The particular focus in the work described is on the prediction of multiphase turbulence due to its relevance in the modelling of bubbly flows in general, including bubble coalescence and break-up, and boiling at a wall. Overall, a satisfactory accuracy is obtained in the prediction of liquid velocities and void fraction distributions in all conditions, including upward and downward flows, and wall-peaked and core-peaked void profiles, when values of the bubble diameter are specified from experimental data. Due to its importance for the correct prediction of the turbulence level in these flows, a bubble-induced turbulence model is introduced, starting from an existing formulation. Source terms due to drag are included in the turbulence kinetic energy and the turbulence energy dissipation rate equations of the k-ε turbulence model, and optimisation of the turbulence source gives velocity fluctuation predictions in agreement with data. After comparisons with data, improvement in the predictions of other turbulence models is also demonstrated, with a Reynolds stress formulation based on the SSG (Speziale et al., 1991) pressure–strain model and the same bubble-induced turbulence model accurately predicting the two-phase flows and the anisotropy of the turbulence field. The same database is also exploited to evaluate different drag models and the advantages of including the effect of the bubble aspect ratio. Following experimental evidence, the model of Tomiyama et al. (2002) is used which assumes that the bubble shape is closer to spherical near a wall and employs a correlation to calculate the aspect ratio. An increase in the drag coefficient due to the higher aspect ratio increases the accuracy of calculated velocity profiles in the near-wall region, even if additional validation is still required due to the possible loss of accuracy in the pipe centre
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