Développement et validation d’un outil numérique de prédiction de l’indice d’isolement acoustique aux bruits d’impact

Ce mémoire présente une approche basée sur la méthode des matrices de transfert (TMM) pour la modélisation du bruit d'impact dans les structures. L'objectif est de développer un modèle précis et robuste pour prédire le niveau sonore d’une structure multicouche excitée par une machine à chocs standard. Le mémoire se compose d’une introduction générale, d’une revue de la littérature sur le bruit d’impact et les méthodes de modélisation existantes, ainsi que de chapitres détaillant la modélisation de la puissance injectée par la machine à chocs standard et trois méthodes de prédiction du bruit d’impact de structures multicouches : la méthode énergétique, la TMM et une méthode combinant l’approche modale et la TMM. Des calculs numériques (éléments finis) et des mesures expérimentales sont utilisés pour comparer les méthodes susmentionnées. En particulier, le modèle TMM s'est avéré fiable pour prédire l’isolement aux bruits d’impact dans les bâtiments

Morphological diversity and hyoscyamine/scopolamine contents in twelve Algerian samples of Datura stramonium L. of different origin

Morphological diversity was estimated on 15 phenotypic characters of Datura stramonium from twelve samples of different origin; the Algerian distribution of that species extends from Nedroma (extreme western Algeria : semi-arid bioclimatic stage) to El Kala (at the Algerian-Tunisian border: humid bioclimatic stage). Seeds from these twelve samples were collected and then grown in similar pedoclimatic conditions. Measurements were carried out 60 days after sowing. Results show that these twelve samples were significantly different for the measured traits (leaf area, length of the flowers, number of ramifications, number and biometrics of the capsules and height of the plants). Principal component analysis (PCA ) and Factorial discriminant analysis (FDA) were used to discriminate the origins of the samples from their studied characters. The canonical averages of the twelve samples were significantly different, especially in the biometric traits including mature plants, capsules and seeds. The alkaloid content (hyoscyamine and scopolamine) of the twelve samples seems to be influenced by the geographical and bioclimatic distribution. In addition, the most alkaloid productive samples were generally those that invest more in biomass production (leaf area, height and collar diameter of plants)La diversité morphologique a été estimée sur 15 caractères phénotypiques de douze provenances de Datura stramonium L. dont la répartition s'étend de Nedroma (extrême Ouest algérien: étage bioclimatique semi-aride) jusqu'à El Kala (à la frontière algéro-tunisienne: étage bioclimatique humide). Pour ce faire, les graines des 12 provenances ont été récoltées puis cultivées dans des conditions pédoclimatiques similaires. Le suivi a ensuite été fait depuis la germination de la graine jusqu'à la maturité des capsules. Les résultats obtenus montrent que les douze provenances sont significativement différentes pour les caractères mesurés (surface foliaire, longueur des fleurs, nombre de ramifications, nombre de capsules par plant, biométrie des capsules, hauteur et diamètre au collet des plantes). L'analyse en composantes principales (ACP) et l'analyse factorielle discriminante (AFD) ont été appliquées pour discriminer les provenances à partir des caractères étudiés. Les moyennes canoniques des douze provenances sont significativement différentes notamment pour les caractères biométriques des capsules, des graines et des plantes matures. La teneur en alcaloïdes (hyoscyamine et scopolamine) des 12 provenances semble être influencée par la répartition géographique et bioclimatique. Par ailleurs, les provenances les plus productrices en alcaloïdes sont généralement celles qui investissent le plus dans la production de biomasse (surface foliaire, hauteur et diamètre au collet des plantes)

Optimization of the Culture Medium Composition to Improve the Production of Hyoscyamine in Elicited Datura stramonium L. Hairy Roots Using the Response Surface Methodology (RSM)

Traditionally, optimization in biological analyses has been carried out by monitoring the influence of one factor at a time; this technique is called one-variable-at-a-time. The disadvantage of this technique is that it does not include any interactive effects among the variables studied and requires a large number of experiments. Therefore, in recent years, the Response Surface Methodology (RSM) has become the most popular optimization method. It is an effective mathematical and statistical technique which has been widely used in optimization studies with minimal experimental trials where interactive factors may be involved. This present study follows on from our previous work, where RSM was used to optimize the B5 medium composition in [NO3−], [Ca2+] and sucrose to attain the best production of hyoscyamine (HS) from the hairy roots (HRs) of Datura stramonium elicited by Jasmonic Acid (JA). The present paper focuses on the use of the RSM in biological studies, such as plant material, to establish a predictive model with the planning of experiments, analysis of the model, diagnostics and adjustment for the accuracy of the model. With the RSM, only 20 experiments were necessary to determine optimal concentrations. The model could be employed to carry out interpolations and predict the response to elicitation. Applying this model, the optimization of the HS level was 212.7% for the elicited HRs of Datura stramonium, cultured in B5-OP medium (optimized), in comparison with elicited HRs cultured in B5 medium (control). The optimal concentrations, under experimental conditions, were determined to be: 79.1 mM [NO3−], 11.4 mM [Ca2+] and 42.9 mg/L of sucrose

Diversité morphologique et teneur en hyoscyamine/scopolamine de douze provenances algériennes de Datura stramonium L.

Morphological diversity and hyoscyamine/scopolamine contents in twelve Algerian samples of Datura stramonium L. of different origin. Morphological diversity was estimated on 15 phenotypic characters of Datura stramonium from twelve samples of different origin ; the Algerian distribution of that species extends from Nedroma (extreme western Algeria : semi-arid bioclimatic stage) to El Kala (at the Algerian-Tunisian border : humid bioclimatic stage). Seeds from these twelve samples were collected and then grown in similar pedoclimatic conditions. Measurements were carried out 60 days after sowing. Results show that these twelve samples were significantly different for the measured traits (leaf area, length of the flowers, number of ramifications, number and biometrics of the capsules and height of the plants). Principal component analysis (PCA) and Factorial discriminant analysis (FDA) were used to discriminate the origins of the samples from their studied characters. The canonical averages of the twelve samples were significantly different, especially in the biometric traits including mature plants, capsules and seeds. The alkaloid content (hyoscyamine and scopolamine) of the twelve samples seems to be influenced by the geographical and bioclimatic distribution. In addition, the most alkaloid productive samples were generally those that invest more in biomass production (leaf area, height and collar diameter of plants).La diversité morphologique a été estimée sur 15 caractères phénotypiques de douze provenances de Datura stramonium L. dont la répartition s’étend de Nedroma (extrême Ouest algérien : étage bioclimatique semi-aride) jusqu’à El Kala (à la frontière algéro-tunisienne : étage bioclimatique humide). Pour ce faire, les graines des 12 provenances ont été récoltées puis cultivées dans des conditions pédoclimatiques similaires. Le suivi a ensuite été fait depuis la germination de la graine jusqu’à la maturité des capsules. Les résultats obtenus montrent que les douze provenances sont significativement différentes pour les caractères mesurés (surface foliaire, longueur des fleurs, nombre de ramifications, nombre de capsules par plant, biométrie des capsules, hauteur et diamètre au collet des plantes). L’analyse en composantes principales (ACP) et l’analyse factorielle discriminante (AFD) ont été appliquées pour discriminer les provenances à partir des caractères étudiés. Les moyennes canoniques des douze provenances sont significativement différentes notamment pour les caractères biométriques des capsules, des graines et des plantes matures. La teneur en alcaloïdes (hyoscyamine et scopolamine) des 12 provenances semble être influencée par la répartition géographique et bioclimatique. Par ailleurs, les provenances les plus productrices en alcaloïdes sont généralement celles qui investissent le plus dans la production de biomasse (surface foliaire, hauteur et diamètre au collet des plantes).Morsli Abdelkader, Derridj Arezki, Khelifi-Slaoui Majda, Bakiri Nouara, Amdoun Ryad, Khelifi Lakhdar. Diversité morphologique et teneur en hyoscyamine/scopolamine de douze provenances algériennes de Datura stramonium L.. In: Revue d'Écologie (La Terre et La Vie), tome 66, n°3, 2011. pp. 291-302

The Desirability Optimization Methodology; a Tool to Predict Two Antagonist Responses In Biotechnological Systems: Case of Biomass Growth and Hyoscyamine Content in Elicited Datura starmonium Hairy Roots

International audienceBackground: The use of the desirability function approach combined with the response surface methodology (RSM), also called Desirability Optimization Methodology (DOM), has been successfully applied to solve medical, chemical, and technological questions. It is particularly efficient for the determination of the optimal conditions in natural or industrial processes involving different factors leading to the antagonist responses. Objectives: Surprisingly, DOM has never been applied to the research programs devoted to the study of plant responses to the complex environmental changes, and thus to biotechnological questions. Materials and Methods: In this article, DOM is used to study the response of Datura stramonium hairy roots (HRs), obtained by genetic transformation with Agrobacterium rhizogenes A(4) strain, subjected to the jasmonate treatments. Results: Antagonist effects on the growth and tropane alkaloid biosynthesis arc confirmed. With a limited number of experimental conditions, it is shown that 0.06 mM jasmonic acid (JA) applied for 24 h leads to an optimal compromise. Hyoscyamine levels increase by up to 290% after 24 h and this treatment does not significantly inhibit biomass growth. Conclusions: It is thus demonstrated that the use of DOM can efficiently - with a minimized number of replicates - leads to the optimization of the biotechnological processes

Optimization of Synthesis, Characterization and Cytotoxic Activity of Seleno-Capparis spionosa L. Polysaccharide

In this study, an experiment was designed to optimize the synthesis of seleno-Capparis spionosa L. polysaccharide (Se-CSPS) by response surface methodology. Three independent variables (reaction time, reaction temperature and ratio of Na2SeO3 to CSPS) were tested. Furthermore, the thermal stability, particle size, shape and cytotoxic activity of Se-CSPS in vitro were investigated. The optimum reaction conditions were obtained shown as follows: reaction time 7.5 h, reaction temperature 71 °C, and ratio of Na2SeO3 to CSPS 0.9 g/g. Under these conditions, the Se content in Se-CSPS reached 5.547 mg/g, which was close to the predicted value (5.518 mg/g) by the model. The thermal stability, particle size and shape of Se-CSPS were significantly different from those of CSPS. Additionally, a MTT assay indicated that the Se-CSPS could inhibit the proliferation of human gastric cancer SGC-7901 cells in a dose-dependent manner