Methane Occurrences in Aquifers Overlying the Barnett Shale Play with a Focus on Parker County, Texas

Clusters of elevated methane concentrations in aquifers overlying the Barnett Shale play have been the focus of recent national attention as they relate to impacts of hydraulic fracturing. The objective of this study was to assess the spatial extent of high dissolved methane previously observed on the western edge of the play (Parker County) and to evaluate its most likely source. A total of 509 well water samples from 12 counties (14,500 km2) were analyzed for methane, major ions, and carbon isotopes. Most samples were collected from the regional Trinity Aquifer and show only low levels of dissolved methane (85% of 457 unique locations 20 mg/L) are limited to a few spatial clusters. The Parker County cluster area includes historical vertical oil and gas wells producing from relatively shallow formations and recent horizontal wells producing from the Barnett Shale (depth of â ¼1500 m). Lack of correlation with distance to Barnett Shale horizontal wells, with distance to conventional wells, and with well density suggests a natural origin of the dissolved methane. Known commercial very shallow gas accumulations (<200 m in places) and historical instances of water wells reaching gas pockets point to the underlying Strawn Group of Paleozoic age as the main natural source of the dissolved gas.Article impact statement: Dissolved methane in aquifers over the Barnett play is infrequent, thermogenic but natural, and related to localized shallow gas accumulations.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/137724/1/gwat12508-sup-0001-supinfo.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/137724/2/gwat12508_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/137724/3/gwat12508.pd

Transition and control in rotating-disk boundary-layer

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Etude du transfert thermique dans un réacteur-échangeur à écoulement laminaire.

Les réacteurs-échangeurs micro-fluidiques permettent d'effectuer des réactions chimiques complexes sur des échantillons de taille réduite et d'analyser rapidement les produits obtenus. Le contrôle de la réaction chimique nécessite la maîtrise de deux processus fondamentaux : le mélange optimal des réactifs et le contrôle de la température en tout point du réacteur. En micro-fluidique, le mélange peut être assuré par le phénomène physique d'advection chaotique. Notre équipe a développé un mélangeur chaotique statique appelé ""MLLM"" (Multi-Level Laminating Mixer) qui approche au plus près la transformation du boulanger permettant ainsi un mélange efficace (Carrière, Phys. Fluids, 2007 ; Liao et al., Lab Chip, 2012 ; Creyssels et al., Int. J. Heat Mass Transfer, 2015). La présente étude vise à montrer la pertinence de ce dispositif utilisé comme un échangeur thermique pour des fluides, des débits et des tailles de canaux correspondant à ceux présents dans les micro-réacteurs fluidiques. Des mesures expérimentales de l'efficacité thermique du MLLM ont été réalisées en employant de l'eau et des mélanges d'eau et de glycérol. Des simulations numériques de l'écoulement au sein du mélangeur-échangeur ont également été menées (code OpenFOAM) et les résultats obtenus sont directement comparés aux résultats expérimentaux. Enfin, une comparaison directe de l'efficacité thermique avec le cas théorique du tube droit de Graetz est présentée

Evaluation of Candidate Reference Genes for Gene Expression Normalization in Brassica juncea Using Real Time Quantitative RT-PCR

The real time quantitative reverse transcription PCR (qRT-PCR) is becoming increasingly important to gain insight into function of genes. Given the increased sensitivity, ease and reproducibility of qRT-PCR, the requirement of suitable reference genes for normalization has become important and stringent. It is now known that the expression of internal control genes in living organism vary considerably during developmental stages and under different experimental conditions. For economically important Brassica crops, only a couple of reference genes are reported till date. In this study, expression stability of 12 candidate reference genes including ACT2, ELFA, GAPDH, TUA, UBQ9 (traditional housekeeping genes), ACP, CAC, SNF, TIPS-41, TMD, TSB and ZNF (new candidate reference genes), in a diverse set of 49 tissue samples representing different developmental stages, stress and hormone treated conditions and cultivars of Brassica juncea has been validated. For the normalization of vegetative stages the ELFA, ACT2, CAC and TIPS-41 combination would be appropriate whereas TIPS-41 along with CAC would be suitable for normalization of reproductive stages. A combination of GAPDH, TUA, TIPS-41 and CAC were identified as the most suitable reference genes for total developmental stages. In various stress and hormone treated samples, UBQ9 and TIPS-41 had the most stable expression. Across five cultivars of B. juncea, the expression of CAC and TIPS-41 did not vary significantly and were identified as the most stably expressed reference genes. This study provides comprehensive information that the new reference genes selected herein performed better than the traditional housekeeping genes. The selection of most suitable reference genes depends on the experimental conditions, and is tissue and cultivar-specific. Further, to attain accuracy in the results more than one reference genes are necessary for normalization

The amyloid precursor protein controls PIKfyve function

While the Amyloid Precursor Protein (APP) plays a central role in Alzheimer's disease, its cellular function still remains largely unclear. It was our goal to establish APP function which will provide insights into APP's implication in Alzheimer's disease. Using our recently developed proteo-liposome assay we established the interactome of APP's intracellular domain (known as AICD), thereby identifying novel APP interactors that provide mechanistic insights into APP function. By combining biochemical, cell biological and genetic approaches we validated the functional significance of one of these novel interactors. Here we show that APP binds the PIKfyve complex, an essential kinase for the synthesis of the endosomal phosphoinositide phosphatidylinositol-3,5-bisphosphate. This signalling lipid plays a crucial role in endosomal homeostasis and receptor sorting. Loss of PIKfyve function by mutation causes profound neurodegeneration in mammals. Using C. elegans genetics we demonstrate that APP functionally cooperates with PIKfyve in vivo. This regulation is required for maintaining endosomal and neuronal function. Our findings establish an unexpected role for APP in the regulation of endosomal phosphoinositide metabolism with dramatic consequences for endosomal biology and important implications for our understanding of Alzheimer's disease

Experimental investigation of heat transfer over drag-reducing riblets

International audienceThe effect of longitudinal and drag-reducing riblets on heat transfer in a turbulent boundary layer is investigated. Systematic previous studies of turbulent flows over'V'-shaped riblets have shown that a drag-reducing regime is observed when the height of the ribs and their spacing are approximately 15 in wall units [8, 1]. The experimental results presented here indicate that drag-reducing riblets surfaces are also heat-transfer reducing surfaces and suggest that the so-called Reynolds analogy remains valid even with microgrooves over the boundary wall