La flottille du Grand Canal de Versailles à l’époque de Louis XIV : diversité, technicité et prestige

While the splendour and greatness of the Grand Canal of Versailles has often been discussed, the impressive flotilla that evolved there from 1669, and the importance of the staff that was allocated to it have rarely been evoked. There is no doubt that the gathering of these various ships participated in the demonstration of the king’s splendour. However, it should not be studied only for its aesthetic, playful, and festive aspects, but also deserves to be examined for its scientific dimension. Indeed, the flotilla of Louis XIV was not only constituted of sailing ships, rowboats, gondolas and barges, it also comprised merchant and war ships, frigates, galleys, hoys, brigantines… It was, therefore, closely connected to French maritime history. In addition, to meet such an encyclopaedic initiative, typical ships of a region or a country were brought in (gondola, peota, English yachts…). Furthermore, the Grand Canal was also a pretext for inventors to carry out technical experiments, testing their machines there. Finally, the construction of these prestigious ships followed a well-defined process. Ordered in the ports of France, they were for the most part dismantled and sent by inland waterways. Correspondents supervised the transport in order to be sure of the exact reassembly of the pieces at the time of the receipt

Sarcoïdose et HTLV-1 en Martinique

La sarcaïdose, en France, est prépondérante chez les Antillais. Le virus HTLV-1 est endémique en Martinique. Nous avons recherché s'il existait un lien de causalité entre l'HTLV-1 et la sarcoïdose chez les patients martiniquais. Nous avons retrouvé trois cas de sérologie HTLV-1 positive sur dix neufs cas de sarcoïdoses histologiquement confirmés. Nous ne pouvons pas conclure à un lien de causalité entre la sarcoïdose et l'HTLV-1. Mais la recherche pourrait être approfondie, puisque des études ont montré une activité de syncytium et de reverse transcriptase dans des sites actifs de la maladie.FORT-DE-FRANCE-CHRU-BU (972332102) / SudocPARIS6-Bibl.Pitié-Salpêtrie (751132101) / SudocPARIS-BIUM (751062103) / SudocSudocFranceF

Empirical potential and elasticity theory modelling of interstitial dislocation loops in UO2 for cluster dynamics application

Durant l'irradiation en pile, la microstructure de l'UO2 évolue et provoque une dégradation du matériau et une dérive de ses propriétés d'usage. Les modèles cinétiques utilisés pour décrire cette évolution tels que la Dynamique d'Amas (code CRESCENDO) traitent les éléments micro-structuraux principaux que sont les cavités et les boucles de dislocation interstitielles, et présentent une description relativement grossière de la thermodynamique des boucles. Pour répondre à cette insuffisance, ce travail de thèse a conduit à l'élaboration d'un modèle thermodynamique de boucles de dislocation interstitielles sur la base de calculs en potentiels empiriques.Le modèle tient compte de deux types de boucles de dislocation interstitielles occupant différents domaines de tailles:Type 1:Les boucles apparentées aux partielles de Frank des matériaux C.F.C. stables aux petites tailles.Type 2: Les boucles parfaites de vecteur de Burgers (a/2)(110) stables aux grandes tailles.L'expression analytique utilisée pour décrire les boucles de dislocation interstitielles est la formule générale d'énergie élastique des boucles de dislocation circulaires à laquelle des paramètres ont été ajoutés afin de tenir compte de l'énergie de cœur dont les effets sont importants aux petites tailles. Les paramètres ont été déterminés par les calculs en potentiels empiriques des énergies de formation des boucles de dislocation prismatiques orthogonales. L'effet de la réorientation des plans d'habitat boucles de dislocation parfaites est pris en compte par interpolation. La typologie des boucles proposées par le modèle est ainsi compatible avec les observations MET.During irradiation in reactor, the microstructure of UO2 changes and deteriorates, causing modifications of its physical and mechanical properties. The kinetic models used to describe these changes such as cluster dynamics (CRESCENDO calculation code) consider the main microstructural elements that are cavities and interstitial dislocation loops, and provide a rather rough description of the loop thermodynamics. In order to tackle this issue, this work has led to the development of a thermodynamic model of interstitial dislocation loops based on empirical potential calculations.The model considers two types of interstitial dislocation loops on two different size domains:Type 1: Dislocation loops similar to Frank partials in F.C.C. materials which are stable in the smaller size domain.Type 2: Perfect dislocation loops of Burgers vector (a/2)(110) stable in the larger size domain.The analytical formula used to compute the interstitial dislocation loop formation energies is the one for circular loops which has been modified in order to take into account the effects of the dislocation core, which are significant at smaller sizes. The parameters have been determined by empirical potential calculations of the formation energies of prismatic pure edge dislocation loops. The effect of the habit plane reorientation on the formation energies of perfect dislocation loops has been taken into account by a simple interpolation method. All the different types of loops seen during TEM observations are thus accounted for by the model

Histoire du Finistère de la formation du quaternaire à la fin de l'ère romaine

National audienc

Changes in surface temperatures reveal the thermal challenge associated with catastrophic moult in captive Gentoo penguins

Once a year, penguins undergo a catastrophic moult replacing their en=re plumage during a fas=ng period on land or on sea-ice during which =me individuals can lose 45% of their body mass. In penguins, new feather synthesis precedes the loss of old feathers leading to an accumula=on of two feathers layers (double coat) before the old plumage is shed. We hypothesize that the combina=on of the high metabolism required for new feathers synthesis and the poten=ally high thermal insula=on linked to the double coat could lead to a thermal challenge requiring addi=onal peripheral circula=on to thermal windows to dissipate extraheat. To test this hypothesis, we measured the surface temperature of different body regions of cap=ve Gentoo penguins (Pygoscelis papua) throughout the moult under constant environmental condi=ons. The surface temperature of the main body trunk decreased during the ini=al stages of the moult, therefore sugges=ng a higher thermal insula=on. On the opposite, the periorbital region, a poten=al proxy of core temperature in birds, increased during these same early moul=ng stages. The surface temperature of bill, flipper and foot (thermal windows) tended to ini=ally increase during the moult period, highligh=ng the likely need for extra heat dissipa=on in moul=ng penguins. These results raise ques=ons regarding the thermoregulatory capaci=es of wild penguins during the challenging period of moul=ng on land in the current context of global warming

Physiological Evaluation of Anomalous Aortic Origin of a Coronary Artery Using Computed Tomography-Derived Fractional Flow Reserve.

Background With the emergence of coronary computed tomography (CT) angiography, anomalous aortic origin of a coronary artery (ANOCOR) is more frequently diagnosed. Fractional flow reserve derived from CT (FFRCT) is a noninvasive functional test providing anatomical and functional evaluation of the overall coronary tree. These unique features of anatomical and functional evaluation derived from CT could help for the management of patients with ANOCOR. We aimed to retrospectively evaluate the physiological and clinical impact of FFRCT analysis in the ANOCOR registry population. Methods and Results The ANOCOR registry included patients with ANOCOR detected during invasive coronary angiography or coronary CT angiography between January 2010 and January 2013, with a planned 5-year follow-up. We retrospectively performed FFRCT analysis in patients with coronary CT angiography of adequate quality. Follow-up was performed with a clinical composite end point (cardiac death, myocardial infarction, and unplanned revascularization). We obtained successful FFRCT analyses and 5-year clinical follow-up in 54 patients (average age, 60±13 years). Thirty-eight (70%) patients had conservative treatment, and 16 (30%) patients had coronary revascularization after coronary CT angiography. The presence of an ANOCOR course was associated with a moderate reduction of FFRCT value from 1.0 at the ostium to 0.90±0.10 downstream the ectopic course and 0.82±0.11 distally. No significant difference in FFRCT values was identified between at-risk and not at-risk ANOCOR. After a 5-year follow-up, only one unplanned percutaneous revascularization was reported. Conclusions The presence of ANOCOR was associated with a moderate hemodynamic decrease of FFRCT values and associated with a low risk of cardiovascular events after a 5-year follow-up in this middle-aged population