Follicle-Stimulating Hormone Receptor: Advances and Remaining Challenges

International audienc

Investigation of tetrazine reactivity towards C-nucleophiles: pyrazolone-based modification of biomolecules

International audienceChemoselective, biocompatible ligation reactions are the key components for efficient and modular access to biomolecular scaffolds. Tetrazine ligation leads to the formation of a mixture of isomers, which makes reaction monitoring, purification and characterization of conjugates difficult. We report herein a modified tetrazine ligation strategy based on the use of a pyrazolone coupling partner, which provides a single molecule conjugate

Structure of hydrothermal convection in the Upper Rhine Graben as inferred from corrected temperature data and basin-scale numerical models

International audienceGeothermal anomalies in sedimentary basins are strongly controlled by fluid circulation within permeable zones. This study presents a new compilation of newly corrected bottom-hole temperature data in the French part of the Upper Rhine Graben, where the Soultz-sous-Forêts temperature anomaly is locked beneath a local horst structure. After a geostatistically constrained interpolation procedure, maps and cross-sections are extracted from the 3D thermal block, together with the associated standard deviations. Thermal anomalies are preferentially associated with the thickest zones of the permeable fractured Buntsandstein (sandstones) formation, in apparent contradiction with previous models where two major fault zones were suggested to control fluid flow. The underlying fractured granitic basement hosts fluid circulation patterns which are apparently controlled at large-scale by the inclined basement-sediments interface. Based on these observations, numerical models of hydrothermal convection including an inclined basement-sediments interface, a local horst structure, and realistic petrophysical properties have been carried out. The depth-decrease of permeability, the inclination of the interface and the fixed heat flow condition at the base of the model, explain why only a few upwellings can be triggered. Thermal anomalies and a measured temperature profile can be reproduced when fault permeability equals 10-14 m². Interestingly, structure of convective patterns also exhibits a second hotter upwelling, 8 km east of the Soultz-sous-Forêts upwelling zone, where another geothermal exploration project is now underway. The understanding of hydrothermal convection with realistic fluid and rock properties clearly appears as a predictive tool for geothermal exploration strategie

Estimation of the deep geothermal potential within the Tertiary Limagne basin (French Massif Central): An integrated 3D geological and thermal approach

International audiencehe geothermal potential of a deep sedimentary-rock reservoir, in a Tertiary graben, the Limagne d’Allier basin (Massif Central, France), is assessed. The most interesting geothermal target is identified as a thick basal Tertiary sandstone overlying crystalline Paleozoic basement. The total amount of recoverable energy in this clastic aquifer is estimated at over 500 PJ (500 × 1015 J) in the modelled area. The most promising zones appear along the north-western edges of the basin, where sediment infill is thickest. The methodology used for estimating geothermal potential starts from geological field data. The first step is to obtain a better understanding of the structure and geometry of the target zone, using various data such as field measurements, and borehole and geophysical data. These data are reinterpreted through the construction of a 3D geological model. Inconsistencies are checked and turned into a coherent 3D interpretation. The second step consists in meshing the geological model into an unstructured 3D finite-element mesh where realistic thermal boundary conditions are applied. The temperature field is computed in a third step. The thermal calculation is achieved by assuming a purely conductive behaviour and through comparison with existing borehole profiles. The computed temperatures fit the measurements in the deepest part of the Limagne d’Allier basin, while the potential role of fluid flow is highlighted in its upper part, either within more permeable formations, or around the boreholes. A fourth, final, step maps the geothermal potential (recoverable energy) in the deepest part of the Tertiary graben, where the total amount of geothermal energy available is calculated. The result of this work provides valuable guidelines for geothermal exploration in the area and our methodology can be replicated elsewhere

The follicle-stimulating hormone signaling network in gonadal cells.

International audienceFSH (follicle-stimulating hormone) is a master endocrine regulator of somatic cells of the gonads that support gametogenesis. In the male, FSH dictates the Sertoli cell proliferation rate prior to puberty, then maintains their main biological roles as nurturing cells and physical support to spermatogenesis throughout life. In the female, FSH is instrumental in processing the terminal differentiation phase of folliculogenesis that progressively drives the ovarian follicle to ovulation. The biological function of FSH is transduced by a membrane receptor, the FSH receptor (FSHR). Deciphering the molecular bases of the developmental switch in FSH biological activities is required to gain insights into FSH-induced signaling pathways. This quest has led to the identification of a complex interconnected signaling network affected by testicular paracrine factors, implying not only protein post-translational modifications but also regulation by microRNA and chromatin remodeling. In the female, the emphasis is now placed on deciphering the complex functional relationships between the LHCGR (luteinizing hormone/choriogonadotropin hormone receptor) and the FSHR that trigger intertwined signaling networks in the same granulosa cell type. Breakthroughs in the organization and dynamic functioning of the FSH-induced signaling network are expected to identifying novel regulatory processes and therapeutic strategies for infertilities and contraception

Heat flow variations in the Grenville Province, Canada

International audienc

Heat flow, gravity, and structure of the Abitibi belt, Superior Province, Canada: implications for mantle heat flow

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Epiclastic deposits and ‘horseshoe-shaped’ calderas in Tahiti (Society Islands) and Ua Huka (Marquesas Archipelago), French Polynesia

International audienc