Une chaîne de traitement de l'information géographique au service de l'application de la loi Littoral

L’application de la loi Littoral nécessitait une approche nouvelle de la part de l’État et la mise en œuvre d’outils nouveaux pour une gestion à long terme. L’apport de traitements automatiques de l’information géographique a été ainsi testé au CETE Normandie-Centre sur trois des grands principes posés par cette loi

Contribution à un diagnostic paysager du Pays de Caux (Normandie, France)

En Pays de Caux, la cour-masure, habitat traditionnel, est menacée par l'urbanisation. En raison d'un projet autoroutier, cet élément important du paysage a été cartographié selon une maille de 500m. Cette cartographie a ensuite été poursuivie, à titre d'essai, selon une maille de 100m, et à l'aide des images SPOT

Pilot scale biotransformation of vegetal oil into natural green note flavor using sugar beet leaves as sources of hydroperoxide lyase

Natural green note aromas (GLVs) are highly attractive flavors commonly used in the food industry. These are produced in extremely low levels upon physiological stress in plant organs of any sort. This weak sporadic presence entails a very expensive extraction step to obtain pure GLVs. Therefore catalytic biotransformations of fatty acid sources, the initial substrate for GLVs, have been developed. Enzymatic defense pathways and particularly the LOX pathway produce the major part of GLVs. Unlike GLV molecules that are emitted in the atmosphere, the enzymes are extractible from the plant material. Thus, a combination of plant enzyme extracts and substrate preparations provides all the ingredients for GLV production. Besides, sugar beet leaves present high levels of hydroperoxide lyase among plant sources and are available in large amounts during three months. In this enzymatic pathway, fatty acids are successively transformed by lipase, lipoxygenase and hydroperoxide lyase into aldehydes and alcohols, final compounds of GLVs pathway. Limiting and problematic steps occur with the action of hydroperoxide lyase, when enzymatic catalysis is followed by an enzyme destabilization. Alternative substrates bind irreversibly to the heme group of the enzyme and end the reaction. This poster briefly describes the development of a complete bioprocess for natural GLV production, from hydrolysis to purification. A high level of biotransformation could be achieved using optimum experimental conditions and a cheap source of plant materials

Contribution à un diagnostic paysager du Pays de Caux (Normandie, France )

In the Caux county the existence of the «cour-masure» (yard-cottage), a traditional housing condition is threatened by growing urbanization. The work on a motorway project has involved the cartography of the countryside using 500 metres grid squares. The cartography was then tested with 100 metres grid squares from SPOT imagery.En Pays de Caux, la cour-masure, habitat traditionnel, est menacée par rurbanisation. En raison d'un projet autoroutier, cet élément important du paysage a été cartographié selon une maille de 500 m. Cette cartographie a ensuite été poursuivie, à titre d'essai, selon une maille de 100 m, et à l'aide des images SPOT.En el País de Caux, la urbanización pone en peligro el «patio-granja», vivienda tradicional. Debido a un proyecto de autopista, este elemento importante del paisaje fue cartografiado con una cuadriculación de 500 m. Esta cartografía se reanudó en concepto de prueba con una cuadriculación de 100 m. y mediante imágenes SPOT.Guillopé Patrick, Bourcier Alban, Gigot Philippe. Contribution à un diagnostic paysager du Pays de Caux (Normandie, France ) . In: Mappemonde, 1989/1. pp. 21-23

Etude du glissement du Bouffay (5 août 1981) : réflexions en vue de la prévision et de la prévention

International audienceThe slump of Le Bouffay is one of the movements that occures in the cliffs of the Bessin (Calvados-France). On the 5th of August 1981, at 20 h 05, 1,5 million m3 slip. They are made with marls of Port, limestones of the Besin and clayx and sandstones of the Planet. They form a collapsed part behind an horizontal moved one that lifts and shears the strand. Calculations of stability are made on two models : one model of "poussée et butée" (push and thrust ?) and one model by the methode of perturbations on a non circular slip plane. They prove that the security coefficient F decreases of 3 to 5 % when the foot of the cliff moves 5 m backwards. Several studies are necessary to foresee and prevent new slips.Le glissement du Bouffay fait partie des manifestations d'instabilité des falaises du Bessin (Calvados). Le 5 août 1981, à 20 h 05, 1,5 million de m3 de marnes de Port, calcaires du Bessin et argiles et grès du Planet glissent, formant une partie effondrée derrière une partie déplacée horizontalement qui a soulevé et cisaillé l'estran. Les calculs de stabilité à partir d'un modèle en poussée et butée et d'un modèle par la méthode de perturbations sur une surface non circulaire montrent que 5 m de recul du pied de falaise (soit le 1/4 du recul pour la période 1809-1975) font varier le coefficient F de sécurité de 3 à 5 %. La prévention nécessite de nombreuses études complémentaires

La mesure du temps dans les enregistrements sédimentaires : une nouvelle méthode d’identification des processus d’accommodation ? Exemples pris dans la Molasse marine miocène du bassin de Digne (Alpes de Haute Provence, SE France)

Couëffé Renaud, Tessier Bernadette, Gigot Patrick, Beaudoin Bernard. La mesure du temps dans les enregistrements sédimentaires : une nouvelle méthode d’identification des processus d’accommodation ? Exemples pris dans la Molasse marine miocène du bassin de Digne (Alpes de Haute Provence, SE France). In: Documents des Laboratoires de Géologie, Lyon, n°156, 2002. STRATI 2002. 3ème congrès français de stratigraphie. Lyon, 8-10 juillet 2002. pp. 87-88

The lipoxygenase metabolic pathway in plants: potential for industrial production of natural green leaf volatiles

Lipoxygenase enzymatic pathway is a widely studied mechanism in the plant kingdom. Combined actions of three enzymes: lipase, lipoxygenase (LOX) and hydroperoxide lyase (HPL) convert lipidic substrates such as C18:2 and C18:3 fatty acids into short chain volatiles. These reactions, triggered by cell membrane disruptions, produce compounds known as Green Leaf Volatiles (GLVs) which are C6 or C9-aldehydes and alcohols. These GLVs are commonly used as flavors to confer a fresh green odor of vegetable to food products. Therefore, competitive biocatalytic productions have been developed to meet the high demand in these natural flavors. Vegetable oils, chosen for their lipidic acid profile, are converted by soybean LOX and plant HPL into natural GLVs. However this second step of the bioconversion presents low yield due to the HPL instability and the inhibition by its substrate. This paper will shortly describe the different enzymes involved in this bioconversion with regards to their chemical and enzymatic properties. Biotechnological techniques to enhance their production potentialities will be discussed along with their implication in a complete bioprocess, from the lipid substrate to the corresponding aldehydic or alcoholic flavors

Sugar beet leaves as source of lyase in bioprocess producing green note aldehydes

Sugar beet leaves were used as source of lyase in a biocatalytic process for the production of C6-aldehydes. Their hydroperoxide lyase activity was revealed important. The optimum values of pH and temperature for reactions were respectively 6.7 and 22 °C. A simple and fast process providing high molar conversion of hydroperoxides to aldehydes is proposed. The yield of the main product cis-3-hexenal reached 80% after only 2 min and was stabilised by acidifying the reaction medium to pH 2

Sugar beet leaves as new source of hydroperoxide lyase in a bioprocess producing green-note aldehydes.

Hydroperoxide lyase activity was found in sugar beet leaves. Its optimum pH and temperature were, respectively, 6.7 and 22 degrees C. Under these conditions, conversion of linolenic acid 13-hydroperoxide to cis-3-hexenal with a maximum yield of 80% was reached after only 2 min. The stability of cis-3-hexenal was improved by acidifying the reaction medium. Based on these studies, a bioprocess producing green-note aldehydes in a laboratory-scale was achieved