12 research outputs found

    Estimating an Ex Ante Cost Function for Belgian Arable Crop Farms

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    We estimate a farm-level cost function for Belgian crop farms using FADN data over the study period 1996-2006. We rely on an estimation of farmers' expected yields at the time cropping decisions are made rather than actual yields observed in the FADN data. The use of an ex ante cost function improves the cost function estimation. We subsequently suggest how our cost function can be used in simulations to analyze farmer response to changes in output price risk.cost function estimation, panel data, risk, Agricultural and Food Policy, Crop Production/Industries, Production Economics, Q12, Q18,

    A new cloning system based on the OprI lipoprotein for the production of recombinant bacterial cell wall-derived immunogenic formulations

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    The conjugation of antigens with ligands of pattern recognition receptors (PRR) is emerging as a promising strategy for the modulation of specific immunity. Here, we describe a new Escherichia coli system for the cloning and expression of heterologous antigens in fusion with the OprI lipoprotein, a TLR ligand from the Pseudomonas aeruginosa outer membrane (OM). Analysis of the OprI expressed by this system reveals a triacylated lipid moiety mainly composed by palmitic acid residues. By offering a tight regulation of expression and allowing for antigen purification by metal affinity chromatography, the new system circumvents the major drawbacks of former versions. In addition, the anchoring of OprI to the OM of the host cell is further explored for the production of novel recombinant bacterial cell wall-derived formulations (OM fragments and OM vesicles) with distinct potential for PRR activation. As an example, the African swine fever virus ORF A104R was cloned and the recombinant antigen was obtained in the three formulations. Overall, our results validate a new system suitable for the production of immunogenic formulations that can be used for the development of experimental vaccines and for studies on the modulation of acquired immunity

    Transformation phenomena in superplastic aluminum 7475

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    The process of superplastic forming in 7475 aluminum alloy was analyzed using orientation imaging microscopy (OIM), x-ray diffraction and scanning electron microscopy (SEM). These techniques were used to determine the effect of the superplastic forming on texture, grain boundary character distribution (GBCD), grain size, residual stress and microstructure at different stages of the deformation of specimens deformed in tension. Results indicate that a microstructure is transformed mainly by the grain boundary sliding process that is responsible for rapid randomization of texture. There is also much evidence for crystallographic slip occurring in conjunction with grain boundary sliding. Accommodation of superplastic flow is linked to increased dislocations density in the lattice. At a threshold level, the dislocation density reaches certain saturation level and the nucleation of voids starts. At this threshold strain, the deformation mechanism is altered and superplastic flow proceeds, however, cavities continue to be produced and coalesce due to the grain boundary sliding process. A precipitate free zone is observed during deformation. This zone is more plastic and presents an orientational difference when compared to the grain interior. It is theorized that this precipitate free zone aids in the accommodation of GBS and plays a role in the cavitation process. The Kernel average misorientation function of OIM was used to indicate the level of strain within the grains to explain the formation of cavities

    Estimating an Ex Ante Cost Function for Belgian Arable Crop Farms

    No full text
    We estimate a farm-level cost function for Belgian crop farms using FADN data over the study period 1996-2006. We rely on an estimation of farmers' expected yields at the time cropping decisions are made rather than actual yields observed in the FADN data. The use of an ex ante cost function improves the cost function estimation. We subsequently suggest how our cost function can be used in simulations to analyze farmer response to changes in output price risk

    Uncertainty and technical efficiency in Finnish agriculture: A state-contingent approach

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    In this article, we present one of the first real-world empirical applications of state-contingent production theory. Our state-contingent behavioural model allows us to analyse production under both inefficiency and uncertainty without regard to the nature of producer risk preferences. Using farm data for Finland, we estimate a flexible production model that permits substitutability between state-contingent outputs. We test empirically and reject an assumption that has been implicit in almost all efficiency studies conducted in the last three decades, namely that the production technology is output-cubical, i.e. that outputs are not substitutable between states of nature

    Estimating an ex ante cost function for Belgian arable crop farms

    No full text
    We estimate a farm-level cost function for Belgian crop farms using FADN data over the study period 1996-2006. We rely on an estimation of farmers' expected yields at the time cropping decisions are made rather than actual yields observed in the FADN data. The use of an ex ante cost function improves the cost function estimation. We subsequently suggest how our cost function can be used in simulations to analyze farmer response to changes in output price risk

    The physics behind the fizz in champagne and sparkling wines

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    Bubbles in a glass of champagne may seem like the acme of frivolity to most of people, but in fact they may rather be considered as a fantastic playground for any physicist. Actually, the so-called effervescence process, which enlivens champagne and sparkling wines tasting, is the result of the fine interplay between CO2 dissolved gas molecules, tiny air pockets trapped within microscopic particles during the pouring process, and some both glass and liquid properties. Results obtained concerning the various steps where the CO2 molecule plays a role (from its ingestion in the liquid phase during the fermentation process to its progressive release in the headspace above the tasting glass as bubbles collapse) are gathered and synthesized to propose a self-consistent and global overview of how gaseous and dissolved CO2 impact champagne and sparkling wine science. Physicochemical processes behind the nucleation, rise, and burst of gaseous CO2 bubbles found in glasses poured with champagne and sparkling wines are depicted. Those phenomena observed in close-up through high-speed photography are often visually appealing. I hope that your enjoyment of champagne will be enhanced after reading this fully illustrated review dedicated to the science hidden right under your nose each time you enjoy a glass of champagne. Gérard Liger-Belair: He received his PhD in physical sciences in 2001 from the University of Reims, in France. He received an associate professor position at the University of Reims in 2002, and a full professor position, in 2007, in the same University. He has been researching the physics and chemistry behind the bubbling properties of champagne and sparkling wines for several years. His current interests include the science of bubbles, foams and thin films, and their broad interdisciplinary applications. He is the author of several academic and popular science books. His first book, Uncorked: the science of champagne, published by Princeton University Press, won the 2004 award for the Best Professional/Scholarly Book in Physics from the Association of American Publishers
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