The history of hydrocarbon filling of Danish chalk fields

In an oil reservoir, the geometry of the interface between water and oil is critical in determining the volume of oil trapped below the top seal. If the interface is planar and horizontal, the volume calculation is fairly simple, but if the interface is tilted or undulating, estimation of the volume of the trapped oil is complex as it depends on the combined structural and fluid contact geometry. Since accumulation of the oil may take place over a time span of several million years, while the reservoir is experiencing burial and compaction, the charge history must be studied using dynamic methods that account for these changes and for flow in both the oil and water phases. These processes have been studied quantitatively at the Geological Survey of Denmark and Greenland (GEUS) in a project that has combined the burial model with a fluid flow simulator. The modelling study shows that filling of a chalk reservoir can have a very long and complex history dominated by very low fluid flow rates (cm/year). The resulting modelled present-day situation exhibits a very irregular oil distribution and a non-planar geometry of the fluid contacts, and shows marked similarities to that shown by the field data

A maternal low protein diet has pronounced effects on mitochondrial gene expression in offspring liver and skeletal muscle; protective effect of taurine

<p>Abstract</p> <p>Background</p> <p>Low birth weight is associated with an increased risk of developing impaired glucose tolerance, and eventually type 2 diabetes in adult life. Gestational protein restriction in rodents gives rise to a low birth weight phenotype in the offspring.</p> <p>Results</p> <p>We examined gene expression changes in liver and skeletal muscle of mice subjected to gestational protein restriction (LP) or not (NP), with or without taurine supplementation in the drinking water. LP offspring had a 40% lower birth weight than NP offspring, with taurine preventing half the decrease. Microarray gene expression analysis of newborn mice revealed significant changes in 2012 genes in liver and 967 genes in skeletal muscle of LP offspring. Taurine prevented 30% and 46% of these expression changes, respectively. Mitochondrial genes, especially those involved with oxidative phosphorylation, were more abundantly changed than other genes. The mitochondrial genes were mainly upregulated in liver, but downregulated in skeletal muscle, despite no change in citrate synthase activity in either tissue. Taurine preferentially rescued genes concerned with fatty acid metabolism in liver and with oxidative phosphorylation and TCA cycle in skeletal muscle. A mitochondrial signature was seen in the liver of NP offspring with taurine supplementation, as gene sets for mitochondrial ribosome as well as lipid metabolism were over represented in 4-week-old offspring subjected to gestational taurine supplementation. Likewise, 11 mitochondrial genes were significantly upregulated by gestational taurine supplementation in 4-week-old NP offspring.</p> <p>Conclusions</p> <p>Gestational protein restriction resulted in lower birth weight associated with significant gene expression changes, which was different in liver and muscle of offspring. However, a major part of the birth weight decrease and the expression changes were prevented by maternal taurine supplementation, implying taurine is a key factor in determining expression patterns during development and in that respect also an important component in metabolic fetal programming.</p