Intracellular mechanism of the action of inhibin on the secretion of follicular stimulating hormone and of luteinizing hormone induced by LH-RH in vitro

The FSH secretion-inhibiting action of inhibin in vitro under basal conditions and also in the presence of LH-RH is suppressed by the addition of MIX, a phosphodiesterase inhibitor. In the presence of LH-RH, inhibin reduces significantly the intracellular level of cAMP in isolated pituitary cells. In contrast, the simultaneous addition of MIX and inhibin raises the cAMP level, and this stimulation is comparable to the increase observed when MIX is added alone. These observations suggest that one mode of action of inhibin could be mediated by a reduction in cAMP within the pituitary gonadotropic cell

Corippe

L’homme Ce que nous avons de Corippe ne nous est connu que par son œuvre et par les incipit ou explicit de ses rares manuscrits. Son nom Flavius Cresconius Corippus peut être reconstitué à partir de la tradition manuscrite et des témoignages médiévaux. Son gentilice a été transmis par un manuscrit aujourd’hui perdu de la bibliothèque fondée à Buda par Matthias Corvin. Son premier surnom, Cresconius, se rencontre fréquemment dans l’onomastique de l’Afrique chrétienne. Le second, attesté sous l..

Arnobe (Arnobius)

L’homme Sur Arnobe, dont le nom atteste peut-être une origine grecque, nous ne savons que ce qu’en dit saint Jérôme, peut-être d’après une préface ou une notice qui aurait été placée en tête de ses œuvres. Il enseignait avec succès la rhétorique à Sicca Veneria (El Kef), en Numidie proconsulaire (Tunisie), sous le règne de Dioclétien (284-305), et eut pour élève le futur écrivain Lactance ; des songes l’auraient incité à se convertir au christianisme ; comme l’évêque ne voulait pas lui faire ..

Arnobe (Arnobius)

L’homme Sur Arnobe, dont le nom atteste peut-être une origine grecque, nous ne savons que ce qu’en dit saint Jérôme, peut-être d’après une préface ou une notice qui aurait été placée en tête de ses œuvres. Il enseignait avec succès la rhétorique à Sicca Veneria (El Kef), en Numidie proconsulaire (Tunisie), sous le règne de Dioclétien (284-305), et eut pour élève le futur écrivain Lactance ; des songes l’auraient incité à se convertir au christianisme ; comme l’évêque ne voulait pas lui faire ..

Inversion of the Diffraction Pattern from an Inhomogeneously Strained Crystal using an Iterative Algorithm

The displacement field in highly non uniformly strained crystals is obtained by addition of constraints to an iterative phase retrieval algorithm. These constraints include direct space density uniformity and also constraints to the sign and derivatives of the different components of the displacement field. This algorithm is applied to an experimental reciprocal space map measured using high resolution X-ray diffraction from an array of silicon lines and the obtained component of the displacement field is in very good agreement with the one calculated using a finite element model.Comment: 5 pages, 4 figure

Fronton

L’homme Fronton est né en Numidie, à Cirta (Constantine), au début du iie siècle après Jésus-Christ. Il commença ses études en Afrique (à Carthage ?), puis les compléta à Rome avec Athénodote et Dionysius. A la fin du règne d’Hadrien, il était considéré comme le plus grand orateur et avocat de son temps, ce qui lui valut une brillante carrière (questeur en Sicile. Puis édile et préteur à Rome) et surtout d’être choisi par Antonin le Pieux comme précepteur des futurs empereurs Marc-Aurèle et L..

Biology and Pest Management of the Sunflower Beetle in North Dakota

E-82

Radon in mining exploration of the deposits of the Shaba Copperbelt

Radon in soils has been tested for the exploration of copper-cobalt deposits of the Shaba crescent where uranium is often a pathfinder element. A very simple technique has been developed using a charcoal detector and a reading by a portable scintillator

Carbonation of alkaline paper mill waste to reduce CO2 greenhouse gas emissions into the atmosphere

International audienceThe global warming of Earth's near-surface, air and oceans in recent decades is a direct consequence of anthropogenic emission of greenhouse gases into the atmosphere such as CO2, CH4, N2O and CFCs. The CO2 emissions contribute approximately 60% to this climate change. This study investigates experimentally the aqueous carbonation mechanisms of an alkaline paper mill waste containing about 55 wt% portlandite (Ca(OH)2) as a possible mineralogical CO2 sequestration process. The overall carbonation reaction includes the following steps: (1) Ca release from portlandite dissolution, (2) CO2 dissolution in water and (3) CaCO3 precipitation. This CO2 sequestration mechanism was supported by geochemical modelling of final solutions using PHREEQC software, and observations by scanning electron microscope and X-ray diffraction of final reaction products. According to the experimental protocol, the system proposed would favour the total capture of approx. 218 kg of CO2 into stable calcite/ton of paper waste, independently of initial CO2 pressure. The final product from the carbonation process is a calcite (ca. 100 wt%)-water dispersion. Indeed, the total captured CO2 mineralized as calcite could be stored in degraded soils or even used for diverse industrial applications. This result demonstrates the possibility of using the alkaline liquid–solid waste for CO2 mitigation and reduction of greenhouse effect gases into the atmosphere

Mineral sequestration of CO2 by aqueous carbonation of coal combustion fly-ash

International audienceThe increasing CO2 concentration in the Earth's atmosphere, mainly caused by fossil fuel combustion, has led to concerns about global warming. A technology that could possibly contribute to reducing carbon dioxide emissions is the in-situ mineral sequestration (long term geological storage) or the ex-situ mineral sequestration (controlled industrial reactors) of CO2. In the present study, we propose to use coal combustion fly-ash, an industrial waste that contains about 4.1 wt.% of lime (CaO), to sequester carbon dioxide by aqueous carbonation. The carbonation reaction was carried out in two successive chemical reactions, first, the irreversible hydration of lime. CaO + H2O → Ca(OH)2 second, the spontaneous carbonation of calcium hydroxide suspension. Ca(OH)2 + CO2 → CaCO3 + H2O A significant CaO–CaCO3 chemical transformation (approximately 82% of carbonation efficiency) was estimated by pressure-mass balance after 2 h of reaction at 30 °C. In addition, the qualitative comparison of X-ray diffraction spectra for reactants and products revealed a complete CaO–CaCO3 conversion. The carbonation efficiency of CaO was independent on the initial pressure of CO2 (10, 20, 30 and 40 bar) and it was not significantly affected by reaction temperature (room temperature “20–25”, 30 and 60 °C) and by fly-ash dose (50, 100, 150 g). The kinetic data demonstrated that the initial rate of CO2 transfer was enhanced by carbonation process for our experiments. The precipitate calcium carbonate was characterized by isolated micrometric particles and micrometric agglomerates of calcite (SEM observations). Finally, the geochemical modelling using PHREEQC software indicated that the final solutions (i.e. after reaction) are supersaturated with respect to calcium carbonate (0.7 ≤ saturation index ≤ 1.1). This experimental study demonstrates that 1 ton of fly-ash could sequester up to 26 kg of CO2, i.e. 38.18 ton of fly-ash per ton of CO2 sequestered. This confirms the possibility to use this alkaline residue for CO2 mitigation