44 research outputs found

    Basin tectonic history and paleo-physiography of the pelagian platform, northern Tunisia, using vitrinite reflectance data

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    Constraining the thermal, burial and uplift/exhumation history of sedimentary basins is crucial in the understanding of upper crustal strain evolution and also has implications for understanding the nature and timing of hydrocarbon maturation and migration. In this study, we use Vitrinite Reflectance (VR) data to elucidate the paleo‐physiography and thermal history of an inverted basin in the foreland of the Atlasic orogeny in Northern Tunisia. In doing so, it is the primary aim of this study to demonstrate how VR techniques may be applied to unravel basin subsidence/uplift history of structural domains and provide valuable insights into the kinematic evolution of sedimentary basins. VR measurements of both the onshore Pelagian Platform and the Tunisian Furrow in Northern Tunisia are used to impose constraints on the deformation history of a long‐lived structural feature in the studied region, namely the Zaghouan Fault. Previous work has shown that this fault was active as an extensional structure in Lower Jurassic to Aptian times, before subsequently being inverted during the Late Cretaceous Eocene Atlas I tectonic event and Upper Miocene Atlas II tectonic event. Quantifying and constraining this latter inversion stage, and shedding light on the roles of structural inheritance and the basin thermal history, are secondary aims of this study. The results of this study show that the Atlas II WNW‐ESE compressive event deformed both the Pelagian Platform and the Tunisian Furrow during Tortonian‐Messinian times. Maximum burial depth for the Pelagian Platform was reached during the Middle to Upper Miocene, i.e. prior to the Atlas II folding event. VR measurements indicate that the Cretaceous to Ypresian section of the Pelagian Platform was buried to a maximum burial depth of ~3 km, using a geothermal gradient of 30°C/km. Cretaceous rock samples VR values show that the hanging wall of the Zaghouan Fault was buried to a maximum depth of <2 km. This suggests that a vertical km‐scale throw along the Zaghouan Fault pre‐dated the Atlas II shortening, and also proves that the fault controlled the subsidence of the Pelagian Platform during the Oligo‐Miocene. Mean exhumation rates of the Pelagian Platform throughout the Messinian to Quaternary were in the order of 0.3 mm/year. However, when the additional effect of Tortonian‐Messinian folding is accounted for, exhumation rates could have reached 0.6-0.7 mm/year

    Structural and optical modeling of electro deposited CuInSe2 thin films

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    The ternary semiconductor CuInSe2 is one of the most advantageous materials for the manufacturing of thin film solar cells. In this study, CuInSe2 thin films were prepared at room temperature using the electrodepositing method. The as-prepared films were found to be amorphous. The CuInSe2 films were crystallized in a tubular resistive furnace, and characterized by means of the the X-ray diffraction (XRD) and UV-VIS-NIR spectroscopy techniques. The parameters to optimize are the temperature and duration of the annealing time, and the Cu/In ratio in the precursors

    Arabidopsis thaliana tolerates iron deficiency more than Thellungiella salsuginea by inducing metabolic changes at the root level

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    Several studies have used A. thaliana as a model to identify the physiological and molecular mechanisms underlying iron deficiency tolerance in plants. Here, Arabidopsis thaliana and Thellungiella salsuginea were used to investigate the differential responses to iron deficiency of these two species. Plants were cultivated in hydroponic medium containing 5 or 0 ÎŒM Fe, for 10 days. Results showed that rosette biomass was more reduced in T. salsuginea than in A. thaliana when grown on Fe-deficient medium. As a marker for iron deficiency tolerance, the induction of ferric chelate reductase (FCR) and phosphoenolpyruvate carboxylase (PEPC) activities was observed only in A. thaliana roots. In addition, we found that the accumulation of phenolic acids in roots of N1438 ecotype of A. thaliana was stimulated by Fe deficiency. Furthermore, an increase of flavonoids content in the root and exudates was observed under Fe-deficiency in this ecotype. Unlike other abiotic stresses, it appears that iron deficiency effects were more pronounced in Thellungiella than in Arabidopsis. The higher tolerance of the Arabidopsis plant to iron deficiency may be due to the metabolic changes occurring in the roots

    Sediment impact on phosphorus transport in a river system

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    Transplantation foie–rein combinĂ©e : indications et rĂ©sultats. [Combined liver-kidney transplantation: Indications and results.]

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    PURPOSE: The purpose of this article is to report our experience concerning the indications and results for combined liver-kidney transplantation in our centre. MATERIAL AND METHOD: From July 1991 to October 2006, 26 patients underwent combined liver-kidney transplantation in our establishment. This group comprised 16 men and 10 women with a mean age of 50.1 years (range: 19 to 68 years). The main indications were as follows: hepatorenal polycystic disease, type I hyperoxaluria, cirrhosis associated with end-stage renal failure. RESULT: The median follow-up was 62.73 (+/-50.9) months. Only two patients of this series died, one at 70 months from gastric cancer, and the other at 89 months from cerebral metastases. Nine patients developed surgical complications (29%). Liver function was normal in the 24 surviving patients. Only one case of loss of renal graft was observed at 12 years and this patient is currently on dialysis. The mean creatinine level in these patients (apart from the dialysed patient) at the last follow-up visit was 120.3 (+/-30.43)mumol/l. CONCLUSION: Combined liver-kidney transplantation can be performed with acceptable morbidity and mortality and excellent long-term results
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