Integrated approach to local based biofuel development, An

2011 Summer.Includes bibliographical references.Oilseed crops have potential to replace a portion of the on-farm energy demand currently satisfied by fossil fuel. This dissertation allies mechanical engineering, field testing, and molecular breeding research into an integrated approach to solve problems associated with straight vegetable oil (SVO) production and use on Colorado farms. Four related topics of investigation and activity are reported. To identify an adapted, short-season oilseed crop that could fit into the current High Plains dryland cropping system, a genetic diversity study was conducted on three potential oilseed species: Brassica juncea, Brassica carinata, and Camelina sativa. To illuminate the genetic basis of camelina response to drought stress, a two-year study of quantitative trait loci (QTLs) was implemented under dry and irrigated conditions using 181 recombinant inbred lines (RILS) developed from European cultivars. To understand and eventually manage camelina production, a multi-environmental regional trial of camelina seed yield, oil content, and oil quality was conducted with eight American and European varieties. Extension activities introduced SVO information and technology to farmers in Colorado. Camelina sativa showed better adaptation to semi-arid environments than B. juncea and B. carinata, outyielding them due to camelina's shorter stature, higher harvest index, and greater resistance to flea beetle. Camelina yield, oil content, and linolenic fatty acid (FA) content were higher in cool, wet environments than in warm, dry environments. Linolenic FA content and seed size were negatively correlated (p<0.05) with early flowering time. Earlier flowering was associated with increased seed yield (p<0.01) under dry and hot environments, but with decreased seed yield under irrigation. Environment was a larger source of variation than genotype for all the traits measured in this study. Twenty-nine QTLs were found in camelina for seed yield, oil quality, and drought-tolerance-related traits such as leaf water content and leaf nitrogen content, which could lead to breeding for improvement of camelina performance in semi-arid environments. Some QTLs were shared by multiple traits, suggesting either pleiotropic effects or proximity of genes. The cumulative effect of stable, favorable alleles for seed yield was a 16% increase in yield. Trait responses to moisture varied widely, both in the multi-environmental regional trial using cultivars and in the single-location trial using RILs. The range of trait response reflects variation in plasticity in camelina germplasm. Two analysis methods, namely, additive main effects and multiplicative interaction (AMMI) and the moisture difference value method, were used to detect false positive QTLs and to predict QTL effect in specific environments. AMMI was used successfully to delineate mega-environments within the study region and to identify the best-adapted varieties for these mega-environments. With the QTL data developed in this study, marker-assisted selection could be used to identify camelina varieties adapted to specific environments or to a broad range of environments. Five lines possessing three favorable yield QTLs expressed under drought conditions are undergoing seed increase and additional multi-locational testing for potential release. Oilseed-for-biofuel workshops, crusher demonstrations, and oilseed field days were conducted to demonstrate the feasibility of potential advantages of SVO for farmers wanting an alternative energy source to reduce their use of fossil fuel. A limited number of early adopters are beginning to integrate camelina into their crop rotation. Three small oilseed crushing and processing facilities have been established from collaboration with farmers and other agencies, and another is in the design stage. Two extension fact sheets will be published on camelina production and on biofuel production at a farm scale

Effets d'histoire sur la modélisation du mélange dans le contexte LES

The time history of mixing is known to play a crucial and non-trivial role in non-premixed turbulent combustion. In a first part, Eulerian balance equations are derived for both a flow residence time and a characteristic time of the mixing which the particles gathered in a fluid element have been submitted to in their flow histories. These equations are analyzed and solved in a Large Eddy Simulation (LES) context for a fuel jet mixing with an oxidizer coflow. Then a new SGS model for non-premixed turbulent flames is proposed on the basis of these new concepts

¿Cuántas submuestras de suelo hay que tomar para caracterizar la fertilidad de un lote en La Pampa Ondulada?

El muestreo de suelos para el diagnóstico de la fertilidad y recomendación de fertilización se ha convertido en una práctica corriente en la Región Pampeana. Generalmente, la unidad de manejo es el lote, pero pueden serlo partes del lote, que representen ambientes distintos, como por ejemplo zona alta y zona baja, en las situaciones que sea necesario aplicar manejos diferentes con condiciones de fertilidad contrastantes. De cada unidad de manejo se genera una muestra compuesta, que es la combinación de varias submuestras tomadas de diferentes lugares. Una pregunta que comúnmente se plantea, al momento de realizar el muestro de suelos, es ¿qué cantidad de submuestras es adecuada para caracterizar la fertilidad del lote?Fil: Alvarez, Roberto. Universidad de Buenos Aires. Facultad de Agronomía; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Steinbach, Haydee S.. Universidad de Buenos Aires. Facultad de Agronomía; ArgentinaFil: Bauschen, Bernardo. Universidad de Buenos Aires. Facultad de Agronomía; ArgentinaFil: Enjalbert, Jean Nicolas. Universidad de Buenos Aires. Facultad de Agronomía; Argentin

Identifying the Deleterious Effect of Rare LHX4 Allelic Variants, a Challenging Issue

International audienceLHX4 is a LIM homeodomain transcription factor involved in the early steps of pituitary ontogenesis. To date, 8 heterozygous LHX4 mutations have been reported as responsible of combined pituitary hormone deficiency (CPHD) in Humans. We identified 4 new LHX4 heterozygous allelic variants in patients with congenital hypopituitarism: W204X, delK242, N271S and Q346R. Our objective was to determine the role of LHX4 variants in patients' phenotypes. Heterologous HEK293T cells were transfected with plasmids encoding for wild-type or mutant LHX4. Protein expression was analysed by Western Blot, and DNA binding by electro-mobility shift assay experiments. Target promoters of LHX4 were cotransfected with wild type or mutant LHX4 to test the transactivating abilities of each variant. Our results show that the W204X mutation was associated with early GH and TSH deficiencies and later onset ACTH deficiency. It led to a truncated protein unable to bind to alpha-Gsu promoter binding consensus sequence. W204X was not able to activate target promoters in vitro. Cotransfection experiments did not favour a dominant negative effect. In contrast, all other mutants were able to bind the promoters and led to an activation similar as that observed with wild type LHX4, suggesting that they were likely polymorphisms. To conclude, our study underlines the need for functional in vitro studies to ascertain the role of rare allelic variants of LHX4 in disease phenotypes. It supports the causative role of the W204X mutation in CPHD and adds up childhood onset ACTH deficiency to the clinical spectrum of the various phenotypes related to LHX4 mutations

Toxic effect and inability of L-homoserine to be a nitrogen source for growth of Escherichia coli resolved by a combination of in vivo evolution engineering and omics analyses

L-homoserine is a pivotal intermediate in the carbon and nitrogen metabolism of E. coli. However, this non-canonical amino acid cannot be used as a nitrogen source for growth. Furthermore, growth of this bacterium in a synthetic media is potently inhibited by L-homoserine. To understand this dual effect, an adapted laboratory evolution (ALE) was applied, which allowed the isolation of a strain able to grow with L-homoserine as the nitrogen source and was, at the same time, desensitized to growth inhibition by this amino acid. Sequencing of this evolved strain identified only four genomic modifications, including a 49 bp truncation starting from the stop codon of thrL. This mutation resulted in a modified thrL locus carrying a thrL* allele encoding a polypeptide 9 amino acids longer than the thrL encoded leader peptide. Remarkably, the replacement of thrL with thrL* in the original strain MG1655 alleviated L-homoserine inhibition to the same extent as strain 4E, but did not allow growth with this amino acid as a nitrogen source. The loss of L-homoserine toxic effect could be explained by the rapid conversion of L-homoserine into threonine via the thrL*-dependent transcriptional activation of the threonine operon thrABC. On the other hand, the growth of E. coli on a mineral medium with L-homoserine required an activation of the threonine degradation pathway II and glycine cleavage system, resulting in the release of ammonium ions that were likely recaptured by NAD(P)-dependent glutamate dehydrogenase. To infer about the direct molecular targets of L-homoserine toxicity, a transcriptomic analysis of wild-type MG1655 in the presence of 10 mM L-homoserine was performed, which notably identified a potent repression of locomotion-motility-chemotaxis process and of branched-chain amino acids synthesis. Since the magnitude of these effects was lower in a ΔthrL mutant, concomitant with a twofold lower sensitivity of this mutant to L-homoserine, it could be argued that growth inhibition by L-homoserine is due to the repression of these biological processes. In addition, L-homoserine induced a strong upregulation of genes in the sulfate reductive assimilation pathway, including those encoding its transport. How this non-canonical amino acid triggers these transcriptomic changes is discussed

Advanced modeling of two phase turbulent combustion with strong dilution by burnt gases

Afin de contribuer à l'amélioration des simulations numériques de foyers industriels avec recycle de gaz brûlés et combustible liquide, la modélisation de la combustion turbulente non prémélangée est abordée sous deux de ses aspects : le traitement des problèmes diphasiques et la prise en compte des configurations complexes de mélange (dilution, recirculation interne).Une flamme spray éthanol/oxygène diluée par du dioxyde de carbone est d'abord calculée en LES dans un formalisme Euler-Lagrange et une chimie détaillée pour une résolution atteignant 250 µm. Les conditions d'injection du brouillard de gouttes sont déterminées à partir de mesures expérimentales de granulométrie et d'anémométrie phase Doppler.Dans une seconde partie, un nouveau formalisme de description de la combustion turbulente, basé sur l'introduction de temps caractéristiques de l'histoire du mélange est développé, puis validé en LES sur le cas de référence d'une flamme jet dans un écoulement co-courant vicié.As a contribution to the improvement of numerical simulations of industrial furnaces with flue gas recirculation and liquid fuel, two aspects of the non-premixed turbulent combustion modeling are addressed: the handling of two-phase problems and the treatment of complex mixing configuration, such as dilution and internal recirculation. An ethanol/oxygen spray flame is first solved in an LES, following an Euler-Lagrange formalism, with detailed chemistry and at a resolution reaching 250 µm. The spray injection conditions are determined from granulometry and Doppler-phase anemometry measurements. In a second part, a novel formalism to describe turbulent combustion is developed, based on the introduction of characteristic timescales of the mixing history. It is then validated on the reference case of a jet flame in a vitiated co-flow

Modélisation avancée de la combustion turbulente diphasique en régime de forte dilution par les gaz brûlés

As a contribution to the improvement of numerical simulations of industrial furnaces with flue gas recirculation and liquid fuel, two aspects of the non-premixed turbulent combustion modeling are addressed: the handling of two-phase problems and the treatment of complex mixing configuration, such as dilution and internal recirculation. An ethanol/oxygen spray flame is first solved in an LES, following an Euler-Lagrange formalism, with detailed chemistry and at a resolution reaching 250 µm. The spray injection conditions are determined from granulometry and Doppler-phase anemometry measurements. In a second part, a novel formalism to describe turbulent combustion is developed, based on the introduction of characteristic timescales of the mixing history. It is then validated on the reference case of a jet flame in a vitiated co-flow.Afin de contribuer à l'amélioration des simulations numériques de foyers industriels avec recycle de gaz brûlés et combustible liquide, la modélisation de la combustion turbulente non prémélangée est abordée sous deux de ses aspects : le traitement des problèmes diphasiques et la prise en compte des configurations complexes de mélange (dilution, recirculation interne).Une flamme spray éthanol/oxygène diluée par du dioxyde de carbone est d'abord calculée en LES dans un formalisme Euler-Lagrange et une chimie détaillée pour une résolution atteignant 250 µm. Les conditions d'injection du brouillard de gouttes sont déterminées à partir de mesures expérimentales de granulométrie et d'anémométrie phase Doppler.Dans une seconde partie, un nouveau formalisme de description de la combustion turbulente, basé sur l'introduction de temps caractéristiques de l'histoire du mélange est développé, puis validé en LES sur le cas de référence d'une flamme jet dans un écoulement co-courant vicié

Influence de la conduite en élevage, du transport et du séjour dans les corrales sur les performances des taureaux braves en corrida

Le taureau brave doit réaliser pendant la corrida des efforts physiques de nature très différentes alternant sprint, poussée et endurance. Pour cela il s'appuie sur une musculature adéquate qui doit être mise en place par une préparation adaptée. Notre travail à consisté, au travers l'observation de 24 taureaux depuis, l'élevage jusqu'à la corrida, à identifier les facteurs pouvant altérer les performances des animaux au cours de la lidia. Il apparaît, que dans les deux mois précédant la corrida, l'apport d'une ration équilibrée en nutriments énergétiques et supplémentée en antioxydants et en précurseur de glycogène peut augmenter le niveau de dépense énergétique des taureaux au cours de l'effort. Le transport ainsi que le séjour au corral peuvent fortement modifier les performances des animaux. Il est préférable que les animaux voyagent de nuit et séjournent soit suffisamment longtemps au corral (5 à 7 jours) soit arrivent le matin même de la corrida. Enfin, au cours de leur séjour au corral, les conditions alimentaires et environnementales peuvent également modifier le comportement des taureaux. Il sera nécessaire d'étendre cette étude à d'autres observations complémentaires avant de proposer de nouvelles recommandations pour les éleveurs, les impresarios ainsi que sur l'organisation des corrales.TOULOUSE-EN Vétérinaire (315552301) / SudocTOULOUSE3-BU Santé-Centrale (315552105) / SudocSudocFranceF

LA RELATION TEXTE / IMAGE ESSAI DE MODELISATION DANS UN CORPUS GEOGRAPHIQUE

CAEN-BU Sciences et STAPS (141182103) / SudocSudocFranceF