934 research outputs found

    Assessing farm sustainability with value oriented methods

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    Agricultural policy makers aim to combine strong economic performance with a sustainable use of natural resources. An important step is to move from trying to define sustainability towards developing concrete tools for measuring and promoting achievements in sustainability. Hence, sustainability assessment is inevitably based on strong simplifications both of the theoretical paradigm and of the characteristics of systems of concern. The most known approaches to assess sustainability performance are burden orientated: they assess the costs or potential harm of resource use. These burden-oriented approaches focus on the level of environmental impacts caused by an economic activity compared to another set of environmental impacts, while value-oriented impact assessment analyses how much value has been created with this set of environmental impacts as compared with the use of these resources by other companies. In this paper, an outline of the possibilities and limitations of value-oriented methods to assess farm sustainability will be discussed.sustainability assessment, agriculture, value oriented, Farm Management,

    The emergence and fate of horizontally acquired genes in Escherichia coli

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    Bacterial species, and even strains within species, can vary greatly in their gene contents and metabolic capabilities. We examine the evolution of this diversity by assessing the distribution and ancestry of each gene in 13 sequenced isolates of Escherichia coli and Shigella. We focus on the emergence and demise of two specific classes of genes, ORFans (genes with no homologs in present databases) and HOPs (genes with distant homologs), since these genes, in contrast to most conserved ancestral sequences, are known to be a major source of the novel features in each strain. We find that the rates of gain and loss of these genes vary greatly among strains as well as through time, and that ORFans and HOPs show very different behavior with respect to their emergence and demise. Although HOPs, which mostly represent gene acquisitions from other bacteria, originate more frequently, ORFans are much more likely to persist. This difference suggests that many adaptive traits are conferred by completely novel genes that do not originate in other bacterial genomes. With respect to the demise of these acquired genes, we find that strains of Shigella lose genes, both by disruption events and by complete removal, at accelerated rates

    An intragenic distribution bias of DNA uptake sequences in Pasteurellaceae and Neisseriae

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    Most sequenced strains from Pasteurellaceae and Neisseriae contain hundreds to thousands of uptake sequence (US) motifs in their genome, which are associated with natural competence for DNA uptake. The mechanism of their recognition is still unclear, and I searched for intragenic location patterns of these motifs for clues about their distribution. In all cases, one orientation of the US has a higher occurrence in the reading frame, and in all Pasteurellaceae, the US and the reverse complement motifs are biased towards the gene termini. These findings could help design experimental set-ups to study preferential DNA uptake, thereby further unravelling the phenomenon of natural competence

    An empirical economic model to reveal behaviour characteristics driving the evolution of agriculture in Belgium

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    Effective design of agricultural policies requires an understanding of the drivers behind the evolution of the agricultural sector. This project builds an evolutionary economic model of the Belgian agricultural sector, as a testing ground for new policies. This agent-based model simulates the dairy, cow and pig sector. The model is calibrated to historical data of production and farm diversity during the period 2003 - 2013. Profit maximising agents cannot replicate the historical trends. When assuming heterogeneous behaviours, the actual evolution can be reproduced much more closely. The calibration reveals key behaviour variables. The evolution in the agricultural sector can only be explained when accounting for a resistance to change at farm level or at market level. However, this approach cannot determine the exact location of this resistance. The resistance to change can result from personal convictions of the farmer or from market rigidities and learning effects

    Farm household risk balancing : implications for policy from an EU perspective

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    Purpose - Building on the risk balancing theory and on recent discussions the appropriateness of using farm income maximization as behavioural assumption, this paper extends the risk balancing framework by accounting for business-household interactions. The purpose of this paper is to theoretically introduce the concept of farm household risk balancing, a theoretical framework in which the farm household sets a constraint on the total household-level risk and balances farm-level and off-farm-level risk. Design/methodology/approach - The paper argues that the risk behaviour of farmers is better understood by considering risk at the household level. Using an analytical framework, equations are derived linking the farm activities, off-farm activities, consumption and business and private liquidity. Findings - The framework shows that a farm household that wants to minimize the risk that total household cash flow falls below consumption needs, may exhibit a wide variety of behavioural responses to changes in the policy and economic environment. Social implications - The framework suggests multiple ways for policy makers and individual farmers to support risk management. Originality/value - Risk management is at the core of the agricultural policy and it is of paramount importance to be able to understand behavioural responses to market and policy instruments. This paper contributes to that by suggesting that the focus of current risk analysis and management studies may be too narrowly focused at the farm level

    Sustainability indicators of Iran's developmental plans : application of the sustainability compass theory

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    The main purpose of this study was to analyze Iran's developmental plans in order to examine and compare their direction and conformity with the sustainable development theory via the compass of sustainability. The approach involves a content analysis used in line with qualitative research methodologies. The results indicated that, in the first developmental plans, there was no direct reference to sustainable development. In the second to fifth plans, the main focus was on the social, environmental, and economic dimensions of development; which were common elements seen in the policies of all the plans. An analysis of the fourth plan revealed that expressions related to sustainable development appeared more frequently, indicating a stronger emphasis on sustainable development by decision-makers
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