Stable carbon isotopic compositions of individual aromatic hydrocarbons as source and age indicators in oils from western Australian basins

The present study aims to establish the factors controlling the stable carbon isotopic compositions (d13C) of individual aromatic hydrocarbons analysed by compound specific isotope analysis (CSIA) in crude oils from western Australian petroleum basins of varying age and facies type. This paper reports d13C values of individual aromatic hydrocarbons, like alkylbenzenes, alkylnaphthalenes, alkylphenanthrenes and methylated biphenyls. The main aims are to confirm the origin (source) and age of these oils based on CSIA of selected aromatic compounds and to understand why the Sofer plot is ineffective in establishing the source of western Australian petroleum systems. The bulk d13C of saturated and aromatic hydrocarbon fractions of crude oils have been previously used to differentiate sources, however, many Australian crude oils are not classified correctly using this method. The oils were classified as marine by the d13C values of individual aromatic compounds and as terrigenous based on the bulk d13C data (Sofer plot). The oils where the d13C values of 1,6-DMN and 1,2,5-TMN isomers are most negative are indicative of a marine source, whereas oils with a less negative values for the 1,6-DMN and 1,2,5-TMN isomers are derived from marine source rocks that contain a significant terrigenous component. Similarly, oils with the least negative d13C values for the 1-MP and 1,9-DMP isomers reflect varying inputs of terrigenous organic matter to the their marine source rocks. Plots of P/DBT and Pr/Ph concentration ratios versus d13C values of DMP, 1,6-DMN, 1,2,5-TMN, 1-MP and 1,9-MP are constructed to establish the relative amount of terrigenous organic matter contributing to the source rock of a series of marine oils. The ratios of P/DBT and Pr/Ph plotted against the d13C values of the aromatic isomers (such as 1,6-DMN, 1,2,5-TMN, 1-MP and 1,9-MP) provide a novel and convenient way to discriminate crude oils derived from different source rocks that contain varying amounts of marine and terrigenous organic matter

Biogeochemical maekers from marine environments of the oligocene from the rhine graben (France)

L'étude moléculaire des lipides préservés dans les sédiments de la Série Grise, d'âge Oligocène, provenant de l'extrémité méridionale du fossé rhénan a permis d'affiner notre compréhension des paléoenvironnements de dépôt associés à la naissance, l'évolutThe molecular study of the organic matter preserved in sediments from a Mid-Oligocene formation (Série Grise) from the southern part of the Upper Rhine Graben provides new information about palaeoenvironnements of deposition related to the birth, evoluti

A thermodynamic closure for the simulation of multiphase reactive flows

International audienceA simple thermodynamic closure for the simulation of multiphase reactive flows is presented. It combines a fully explicit thermodynamic closure appropriate for weakly thermal multiphase flow simulations, with the classical variable heat capacity ideal gas thermodynamic closure, commonly used for reactive flows simulations. Each liquid and gas component is assumed to follow the recent Noble-Abel Stiffened Gas equation of state, fully described by a set of five parameters. A new method for setting these parameters is presented and validated through comparisons with NIST references. Comparisons with a well-known cubic equation of state, Soave-Redlich-Kwong, are also included. The Noble-Abel Stiffened-Gas equation of state is then extended as to cope with variable heat capacity, to make the mixture ther-modynamic closure appropriate for multiphase reactive flows

Marqueurs biogéochimiques d'environnements marins de l'oligocène du fossé rhénan

L étude moléculaire des lipides préservés dans les sédiments de la Série Grise, d âge Oligocène, provenant de l extrémité méridionale du fossé rhénan a permis d affiner notre compréhension des paléoenvironnements de dépôt associés à la naissance, l évolution et la mort de la mer du Rupélien . Avant la transgression marine généralisée, l espace rhénan est occupé par un système lacustre à évaporitique, isolé du domaine marin. La contribution allochtone à la matière organique est alors prépondérante. Au contraire, les dépôts du cortège marin transgressif sont nettement marqués par la prédominance des apports autochtones. L évolution des concentrations relatives de ces biomarqueurs peut être corrélée avec les différents cycles transgressif/régressif que connaît le bassin. Dans un premier temps, la mer du Rupélien présente des fonds bien oxygénés puis, brutalement, apparaissent de nombreux marqueurs d anoxie, tels que les dérivés de l isoréniératène, témoignant de l extension de la zone anoxique jusque dans la zone photique. A ce stade, le confinement du bassin est sévère même si, temporairement des connections avec la mer ouverte sont établies. Puis, un vaste appareil deltaïque progradant à partir du domaine périalpin vers le Nord se met en place et rétablit de bonnes conditions de circulation dans le bassin. Les distributions de biomarqueurs sont alors classiquement dominées par différents dérivés de terpènes de végétaux supérieurs. Toutefois, la réapparition des dérivé de l isoréniératène dans un faciès spécifique s intercalant de manière récurrente au sein du cortège continental témoigne de la relative fragilité des connections entretenues entre ces deux bassins adjacents. Dans ce cadre, l étude de dépôts de crue enrichis en matière organique nous a permis d identifier de nouveaux dérivés de terpènes de végétaux supérieurs par RMN : un triterpène tétra-aromatique de la classe du serratane et une série de bis-diterpenoïdes provenant potentiellement de Podocarpaceae.STRASBOURG-Sc. et Techniques (674822102) / SudocSudocFranceF

The effect of origin and genetic processes of low molecular weight aromatic hydrocarbons in petroleum on their stable carbon isotopic compositions

Stable carbon isotopic compositions of individual low molecular weight aromatic hydrocarbons, such as alkylbenzenes, alkylnaphthalenes and alkylphenanthrenes, were measured from a set of oils, mostly from the North-West shelf of Australia, of varying age, facies type and thermal maturity. The objective was to assess the influence of thermal maturity and source during generation of these aromatics on their stable carbon isotopic compositions. For most of the oils studied, δ13C of the aromatic components show a 13C depletion as the degree of methylation increases. For the alkylnaphthalenes, the 13C depletion is most pronounced for low maturity oils compared to high maturity oils. δ13C of the methyl groups of these alkylnaphthalenes were calculated and the resulting data display significant differences between ‘mature’ and ‘immature’ oils, suggesting that isotopically lighter methyl groups are ‘released’ as thermal maturation proceeds. Therefore, we propose an isotopic fractionation associated with the methyl transfer mechanisms affecting low molecular weight aromatic hydrocarbons during diagenesis

A new computational model and its discipline of programming

CNRS 14802E / INIST-CNRS - Institut de l'Information Scientifique et TechniqueSIGLEFRFranc

Programming by multiset transformation

SIGLEAvailable at INIST (FR), Document Supply Service, under shelf-number : 14802 E, issue : a.1990 n.1205 / INIST-CNRS - Institut de l'Information Scientifique et TechniqueFRFranc

Clinical and mutational spectrum in a cohort of 105 unrelated patients with dilated cardiomyopathy.

International audienceDilated Cardiomyopathy (DCM) is one of the leading causes of heart failure with high morbidity and mortality. More than 30 genes have been reported to cause DCM. To provide new insights into the pathophysiology of dilated cardiomyopathy, a mutational screening on 4 DCM-causing genes (MYH7, TNNT2, TNNI3 and LMNA) was performed in a cohort of 105 unrelated DCM (64 familial cases and 41 sporadic cases) using a High Resolution Melting (HRM)/sequencing strategy. Screening of a highly conserved arginine/serine (RS)-rich region in exon 9 of RBM20 was also performed. Nineteen different mutations were identified in 20 index patients (19%), including 10 novels. These included 8 LMNA variants in 9 (8.6%) probands, 5 TNNT2 variants in 5 probands (4.8%), 4 MYH7 variants in 3 probands (3.8%), 1 TNNI3 variant in 1 proband (0.9%), and 1 RBM20 variant in 1 proband (0.9%). One proband was double-heterozygous. LMNA mutations represent the most prevalent genetic DCM cause. Most patients carrying LMNA mutations exhibit conduction system defects and/or cardiac arrhythmias. Our study also showed than prevalence of mutations affecting TNNI3 or the (RS)-rich region of RBM20 is lower than 1%. The discovery of novel DCM mutations is crucial for clinical management of patients and their families because pre-symptomatic diagnosis is possible and precocious intervention could prevent or ameliorate the prognosis

Multi-tissue transcriptomic study reveals the main role of liver in the chicken adaptive response to a switch in dietary energy source through the transcriptional regulation of lipogenesis

The 178 microarrays are MIAME compliant and available in Gene Expression Omnibus (GEO) through GEO Series accession number GSE104042 andplatform number GPL19630.International audienceBackground: Because the cost of cereals is unstable and represents a large part of production charges for meattype chicken, there is an urge to formulate alternative diets from more cost-effective feedstuff. We have recently shown that meat-type chicken source is prone to adapt to dietary starch substitution with fat and fiber. The aim of this study was to better understand the molecular mechanisms of this adaptation to changes in dietary energy sources through the fine characterization of transcriptomic changes occurring in three major metabolic tissues – liver, adipose tissue and muscle – as well as in circulating blood cells.Results: We revealed the fine-tuned regulation of many hepatic genes encoding key enzymes driving glycogenesis and de novo fatty acid synthesis pathways and of some genes participating in oxidation. Among the genes expressed upon consumption of a high-fat, high-fiber diet, we highlighted CPT1A, which encodes a key enzyme in the regulation of fatty acid oxidation. Conversely, the repression of lipogenic genes by the high-fat diet was clearly associated with the downregulation of SREBF1 transcripts but was not associated with the transcript regulation of MLXIPL and NR1H3, which are both transcription factors. This result suggests a pivotal role for SREBF1 in lipogenesis regulation in response to a decrease in dietary starch and an increase in dietary PUFA. Other prospective regulators of de novo hepatic lipogenesis were suggested, such as PPARD, JUN, TADA2A and KAT2B, the last two genes belonging to the lysine acetyl transferase (KAT) complex family regulating histone and non-histone protein acetylation. Hepatic glycogenic genes were also down-regulated in chickens fed a high-fat, high-fiber diet compared to those in chickens fed a starch-based diet. No significant dietary-associated variations in gene expression profiles was observed in the other studied tissues, suggesting that the liver mainly contributed to the adaptation of birds to changes in energy source and nutrients in their diets, at least at the transcriptional level. Moreover, we showed that PUFA deposition observed in the different tissues may not rely on transcriptional changes.Conclusion: We showed the major role of the liver, at the gene expression level, in the adaptive response of chicken to dietary starch substitution with fat and fiber