Minimum Quality Standard and Premium Private Labels

Cet article propose une étude théorique des nouvelles générations de Marques de Distributeurs dans le secteur alimentaire. Nous proposons un modèle original de relation verticale, intégrant l'existence d'un marché intermédiaire de type concurrentiel (marché spot) parallèlement à la mise en place d'une relation contractuelle privilégiée entre une partie des producteurs amont et un distributeur. On montre alors sous quelles conditions les producteurs impliqués et le distributeur vont effectivement mettre en place ce type de démarches. Il apparaît néanmoins qu'à l'inverse des producteurs, les distributeurs et les consommateurs peuvent préférer une amélioration légiférée de la qualité par un renforcement des standards de qualité minimum.Relations verticales;Grande distribution;Sécurité sanitaire;Standard de qualité minimum;Marques de distribution

Phosphate and zinc transport and signalling in plants: toward a better understanding of their homeostasis interaction

Zn and Pi are essential elements for plant growth. Current understanding of the regulation of their homeostasis interaction and signalling cross-talk is presente

FIRMS’ RESPONSES TO NUTRITIONAL POLICIES

The aim of this paper is to examine the effects of nutritional policies on the behavior of firms, particularly in terms of food quality and prices, and to assess the potential impacts of such policies from a public health point of view. We determine how new products that are nutritionally improved can emerge in a market where incumbent firms offer competing unhealthy products. We also highlight a non-intentional effect of such policies: if consumer heterogeneity is high, then an information policy may simultaneously provide health benefits to the population as a whole but worsen the health of consumers that are less aware of nutritional effects. For a given level of nutritional tax, we determine the optimal threshold that firms must meet to avoid taxation. It appears that this threshold must not be too high if the goal of nutritional policies is to increase total health benefits without increasing health disparities between consumers. An increase in the tax level has two opposing effects. On one hand, it improves health benefits for consumers that are less aware of nutrition issues. On the other hand, because it leads to an increase in prices as a result of a reduction in the competition intensity, it decreases the cost-effectiveness of the policy.Nutrition policy, product differentiation, firms’ strategies, taxation, quality standards, public health, Agricultural and Food Policy, Consumer/Household Economics, Demand and Price Analysis, Food Consumption/Nutrition/Food Safety, Food Security and Poverty, Health Economics and Policy, L15, I18, H23,

Minimum Quality Standard and Premium Private Labels

This article gives a theoretical analysis of a new type of private labels in the food sector. We propose an original model of vertical relationship between producers and retailers which takes into account two supply sources through (i) a competitive spot market and (ii) supply contracts. We study how the producers and retailers could cooperate to set up these new labels. However it appears that retailers and consumers could prefer the stepping up of minimum quality standards rather than this type of private labels.Cet article propose une étude théorique des nouvelles générations de Marques de Distributeurs dans le secteur alimentaire. Nous proposons un modèle original de relation verticale, intégrant l'existence d'un marché intermédiaire de type concurrentiel (marché spot) parallèlement à la mise en place d'une relation contractuelle privilégiée entre une partie des producteurs amont et un distributeur. On montre alors sous quelles conditions les producteurs impliqués et le distributeur vont effectivement mettre en place ce type de démarches. Il apparaît néanmoins qu'à l'inverse des producteurs, les distributeurs et les consommateurs peuvent préférer une amélioration légiférée de la qualité par un renforcement des standards de qualité minimum

Coordination between zinc and phosphate homeostasis involves the transcription factor PHR1, the phosphate exporter PHO1, and its homologue PHO1;H3 in Arabidopsis.

Interactions between zinc (Zn) and phosphate (Pi) nutrition in plants have long been recognized, but little information is available on their molecular bases and biological significance. This work aimed at examining the effects of Zn deficiency on Pi accumulation in Arabidopsis thaliana and uncovering genes involved in the Zn-Pi synergy. Wild-type plants as well as mutants affected in Pi signalling and transport genes, namely the transcription factor PHR1, the E2-conjugase PHO2, and the Pi exporter PHO1, were examined. Zn deficiency caused an increase in shoot Pi content in the wild type as well as in the pho2 mutant, but not in the phr1 or pho1 mutants. This indicated that PHR1 and PHO1 participate in the coregulation of Zn and Pi homeostasis. Zn deprivation had a very limited effect on transcript levels of Pi-starvation-responsive genes such as AT4, IPS1, and microRNA399, or on of members of the high-affinity Pi transporter family PHT1. Interestingly, one of the PHO1 homologues, PHO1;H3, was upregulated in response to Zn deficiency. The expression pattern of PHO1 and PHO1;H3 were similar, both being expressed in cells of the root vascular cylinder and both localized to the Golgi when expressed transiently in tobacco cells. When grown in Zn-free medium, pho1;h3 mutant plants displayed higher Pi contents in the shoots than wild-type plants. This was, however, not observed in a pho1 pho1;h3 double mutant, suggesting that PHO1;H3 restricts root-to-shoot Pi transfer requiring PHO1 function for Pi homeostasis in response to Zn deficiency

Functional expression of PHO1 to the Golgi and trans-Golgi network and its role in export of inorganic phosphate.

Arabidopsis thaliana PHO1 is primarily expressed in the root vascular cylinder and is involved in the transfer of inorganic phosphate (Pi) from roots to shoots. To analyze the role of PHO1 in transport of Pi, we have generated transgenic plants expressing PHO1 in ectopic A. thaliana tissues using an estradiol-inducible promoter. Leaves treated with estradiol showed strong PHO1 expression, leading to detectable accumulation of PHO1 protein. Estradiol-mediated induction of PHO1 in leaves from soil-grown plants, in leaves and roots of plants grown in liquid culture, or in leaf mesophyll protoplasts, was all accompanied by the specific release of Pi to the extracellular medium as early as 2-3 h after addition of estradiol. Net Pi export triggered by PHO1 induction was enhanced by high extracellular Pi and weakly inhibited by the proton-ionophore carbonyl cyanide m-chlorophenylhydrazone. Expression of a PHO1-GFP construct complementing the pho1 mutant revealed GFP expression in punctate structures in the pericycle cells but no fluorescence at the plasma membrane. When expressed in onion epidermal cells or in tobacco mesophyll cells, PHO1-GFP was associated with similar punctate structures that co-localized with the Golgi/trans-Golgi network and uncharacterized vesicles. However, PHO1-GFP could be partially relocated to the plasma membrane in leaves infiltrated with a high-phosphate solution. Together, these results show that PHO1 can trigger Pi export in ectopic plant cells, strongly indicating that PHO1 is itself a Pi exporter. Interestingly, PHO1-mediated Pi export was associated with its localization to the Golgi and trans-Golgi networks, revealing a role for these organelles in Pi transport

Segmentation de l’offre et relations entre producteurs et distributeurs . Quelles stratégies de la grande distribution après la crise de la « vache folle »

Le développement des Marques de Distributeurs (MDD) dans le secteur des produits agricoles frais est un phénomène récent, dont l'émergence est étroitement liée aux crises alimentaires et sanitaires des dernières années. Ainsi, en même temps que les pouvoirs publics créaient de nouveaux dispositifs de contrôle sanitaire, resserraient les normes réglementaires de production ou faisaient évoluer la réglementation sur les signes officiels de qualité (SOQ), de nouvelles stratégies de segmentation de l'offre étaient adoptées par certains distributeurs, sur la base d'une implication plus grande au niveau de l'amont agricole. Initiées dans le secteur de la viande, directement touché par la crise de la "vache folle", ces démarches se sont développées ensuite dans d'autres secteurs comme ceux des fruits et légumes, du poisson, des fromages et du vin. En quoi ces démarches modifient-elles l'offre alimentaire proposée aux consommateurs ? En quoi modifient-elles les relations entre les producteurs et les distributeurs et sous quelles conditions les uns et les autres ont-ils intérêt à s'y engager ? Comment ces démarches viennent-elles interagir avec celles des pouvoirs publics et, notamment, le relèvement des standards de qualité minimum ? Ce sont ces questions qui sont examinées dans cette étude à partir de l'exemple de la viande bovine.

Differential performance of two forage species, Medicago truncatula and Sulla carnosa, under water-deficit stress and recovery

The response patterns during water deficit stress and subsequent recovery of two forage species, Medicago truncatula and Sulla carnosa, were studied. After germination and pre-treatment, seedlings were individually cultivated for two months under two irrigation modes: 100% and 33% of field capacity. Measured parameters were plant growth, water relations, leaf osmotic potential, lipid peroxidation, and leaf inorganic (Na+ and K+) and organic (proline and soluble sugars) solute contents, as well as delta-1-pyrroline-5-carboxylate synthase (P5CS) and proline dehydrogenase (PDH) activities. Our results showed that under control conditions, and in contrast to roots, no significant differences were observed in shoot biomass production between the two species. However, when subjected to water-deficit stress, M. truncatula appeared to be more tolerant than S. carnosa (reduction by 50 and 70%, respectively). In the two studied species, water-deficit stress led to an increase in root/shoot ratio and leaf proline and soluble sugar contents, and a decrease in leaf osmotic potential. Enzymatic assay revealed that in the two species, P5CS activity was stimulated whereas that of PDH was inhibited under stress conditions. Despite greater accumulation of proline, sugar, and potassium in leaves of S. carnosa, M. truncatula was more tolerant to water deficit. This was essentially due to its capacity to control tissue hydration and water-use efficiency, in addition to its greater ability to protect membrane integrity. Following stress relief, M. truncatula and S. carnosa showed partial re-establishment of growth capacity

Coordination between zinc and phosphate homeostasis involves the transcription factor PHR1, the phosphate exporter PHO1, and its homologue PHO1;H3 in Arabidopsis

Phosphate over-accumulates in shoots in response to Zn deprivation. Results shown in this article suggest key roles of PHR1 and PHO1 and a counteractive function of PHO1;H3 in controlling root-to-shoot phosphate translocation in Arabidopsi

A Semantical Framework To Engineering WSBPEL Processes

International audienceWeb services promise the interoperability of various applications running on heterogeneous platforms over the Internet, and are gaining more and more attention. Web service composition refers to the process of combining Web services to provide value-added services, which has received much interest in supporting enterprize application integration. Industry standards for Web Service composition, such as WSBPEL, provide the notation and additional control mechanisms for the execution of business processes in Web service collaborations. However, these standards do not provide support for checking interesting properties related to Web Service and process behavior. In an attempt to fill this gap, we describe a formalization of WSBPEL business processes, that adds communications semantics to the specifications of interacting Web services, and uses a formal logic to model their dynamic behavior, which enables their formal analysis and the inference of relevant properties of the systems being built