Building WF16: construction of a PPNA pisé structure in Southern Jordan

The Pre-Pottery Neolithic A (PPNA) period in Southwest Asia is essential for our understanding of the transition to sedentary, agricultural communities. Developments in architecture are key to understanding this transition, but many aspects of PPNA architecture remain elusive, such as construction techniques, the selection of building materials, and the functional use of space. The primary aim of the research described within this contribution was to build a PPNA-like structure in order to answer questions about PPNA architecture in general, while specifically addressing issues raised by the excavation of structures at the site of WF16, Southern Jordan. The second aim was to display a ‘PPNA’ building to visitors in Wadi Faynan to enhance their understanding of the period. The experimental construction based on one of the WF16 structures showed that 1) required materials can be acquired locally; 2) a construction technique using mud layers as described in this paper was likely used; 3) flat, or very slightly dome-shaped, roofs are functional and can also be used as a solid working platform; 4) the WF16 small semi-subterranean buildings appear inappropriate for housing a nuclear family unit

Simple scoring system to predict in-hospital mortality after surgery for infective endocarditis

BACKGROUND: Aspecific scoring systems are used to predict the risk of death postsurgery in patients with infective endocarditis (IE). The purpose of the present study was both to analyze the risk factors for in-hospital death, which complicates surgery for IE, and to create a mortality risk score based on the results of this analysis. METHODS AND RESULTS: Outcomes of 361 consecutive patients (mean age, 59.1\ub115.4 years) who had undergone surgery for IE in 8 European centers of cardiac surgery were recorded prospectively, and a risk factor analysis (multivariable logistic regression) for in-hospital death was performed. The discriminatory power of a new predictive scoring system was assessed with the receiver operating characteristic curve analysis. Score validation procedures were carried out. Fifty-six (15.5%) patients died postsurgery. BMI >27 kg/m2 (odds ratio [OR], 1.79; P=0.049), estimated glomerular filtration rate 55 mm Hg (OR, 1.78; P=0.032), and critical state (OR, 2.37; P=0.017) were independent predictors of in-hospital death. A scoring system was devised to predict in-hospital death postsurgery for IE (area under the receiver operating characteristic curve, 0.780; 95% CI, 0.734-0.822). The score performed better than 5 of 6 scoring systems for in-hospital death after cardiac surgery that were considered. CONCLUSIONS: A simple scoring system based on risk factors for in-hospital death was specifically created to predict mortality risk postsurgery in patients with IE

Le pouvoir calorifique superieur d'especes forestieres mediterraneennes

National audienceHigh calorific value (P.C.S.) represents the maximum of energy released by combustion. It allows the computation of the forest fire heat release. On a dry matter basis or on an ash-free basis datas group the species in classes : - leaves of Erica arborea L., - needles of Pinus halepensis Mill., - leaves of Arbutus unedo L. and top-end sprouts of Ulex parviflorus Pourret, - leaves of Quercus ilex L. and Quercus coccifera L. High calorific values rise with the lignification. High calorific values of these mediterranean species are higher than these of more temperate species, or at least equal to these.Le pouvoir calorifique supérieur (P.C.S.) est le maximum d’énergie que peut dégager une combustion. Il conduit au bilan énergétique d’un incendie de forêt. Rapporté au poids de matière sèche ou au poids de la seule matière organique, le P.C.S. permet de hiérarchiser les végétaux selon leur caractère énergétique Bien que les P.C.S. croissent avec la lignification des tissus, ils conduisent au classement par ordre décroissant : - feuilles de bruyère arborescente, - feuilles de pin d’Alep, - feuilles d’arbousier et pousses terminales d’ajonc épineux, - feuilles de chêne vert et de chêne kermès. Les P.C.S. de ces espèces méditerranéennes sont supérieurs ou au moins égaux à ceux d'espèces de régions plus tempérées

Le pouvoir calorifique superieur d'especes forestieres mediterraneennes

National audienceHigh calorific value (P.C.S.) represents the maximum of energy released by combustion. It allows the computation of the forest fire heat release. On a dry matter basis or on an ash-free basis datas group the species in classes : - leaves of Erica arborea L., - needles of Pinus halepensis Mill., - leaves of Arbutus unedo L. and top-end sprouts of Ulex parviflorus Pourret, - leaves of Quercus ilex L. and Quercus coccifera L. High calorific values rise with the lignification. High calorific values of these mediterranean species are higher than these of more temperate species, or at least equal to these.Le pouvoir calorifique supérieur (P.C.S.) est le maximum d’énergie que peut dégager une combustion. Il conduit au bilan énergétique d’un incendie de forêt. Rapporté au poids de matière sèche ou au poids de la seule matière organique, le P.C.S. permet de hiérarchiser les végétaux selon leur caractère énergétique Bien que les P.C.S. croissent avec la lignification des tissus, ils conduisent au classement par ordre décroissant : - feuilles de bruyère arborescente, - feuilles de pin d’Alep, - feuilles d’arbousier et pousses terminales d’ajonc épineux, - feuilles de chêne vert et de chêne kermès. Les P.C.S. de ces espèces méditerranéennes sont supérieurs ou au moins égaux à ceux d'espèces de régions plus tempérées

Novative Rendering and Physics Engines to Apprehend Special Relativity

International audienceRelativity, as introduced by Einstein, is regarded as one of the most important revolutions in the history of physics. Nevertheless, the observation of direct outcomes of this theory on mundane objects is impossible because they can only be witnessed when relative velocities close the speed of light are involved. These effects are so counterintuitive and contradicting with our daily understanding of space and time that physics students find it hard to learn Special Relativity beyond mathematical equations and to understand the deep implications of the theory. Although we cannot travel at the speed of light for real, Virtual Reality makes it possible to experiment the effects of relativity in a 3D immersive environment. Our project is a framework designed to merge advanced 3D graphics with Virtual Reality interfaces in order to create an appropriate environment to study and learn relativity as well as to develop some intuition of the relativistic effects and the quadri-dimensional reality of space-time. In this paper, we focus on designing and implementing an easy-to-use game-like application : a carom billiard. Our implementation includes relativistic effects in an innovative graphical rendering engine and a non-Newtonian physics engine to treat the collisions. The innovation of our approach lies in the ability i) to render in real-time several relativistic objects, each moving with a different velocity vector (contrary to what was achieved in previous works), ii) to allow for interactions between objects, and iii) to enable the user to interact with the objects and modify the scene. To achieve this, we implement the 4D nature of space-time directly at the heart of the rendering engine, and develop an algorithm allowing to access non-simultaneous past events that are visible to the observers at their specific locations and at a given instant of their proper time. We explain how to retrieve the collision event between the pucks and the cushions of the billiard game and we show several counterintuitive results for very fast pucks. The effectiveness of the approach is demonstrated with snapshots of videos where several independent objects travel at velocities close to the speed of light, c

Designing learning scenarios for a 3D virtual environment: The case of special relativity

International audienceSpecial Relativity, as introduced by Einstein, is regarded as one of the most important revolutions in the history of physics. Nevertheless, the observation of direct outcomes of this theory on mundane objects is impossible because they can only be witnessed when travelling at relative speeds approaching the light velocity c. These effects are so counterintuitive and contradicting with our daily understanding of space and time that physics students find it hard to learn special relativity beyond mathematical equations and to understand the deep implications of the theory. Although we cannot travel at the speed of light, Virtual Reality (VR) makes it possible to experiment the effects of relativity in a 3D immersive environment (a CAVE: Cave Automatic Virtual Environment). The use of the immersive environment is underpinned by the development of dedicated learning scenarios created through a dialectic between VR-related computational constraints and cognitive constraints that include students' difficulties. Investigating student's understanding of relativistic situations (that involve relative speeds close to c) led to the typifying of a cognitive profile that governed the situations to be implemented into the CAVE and the associated learning scenarios

Designing learning scenarios for a 3D virtual environment: The case of special relativity

International audienceSpecial Relativity, as introduced by Einstein, is regarded as one of the most important revolutions in the history of physics. Nevertheless, the observation of direct outcomes of this theory on mundane objects is impossible because they can only be witnessed when travelling at relative speeds approaching the light velocity c. These effects are so counterintuitive and contradicting with our daily understanding of space and time that physics students find it hard to learn special relativity beyond mathematical equations and to understand the deep implications of the theory. Although we cannot travel at the speed of light, Virtual Reality (VR) makes it possible to experiment the effects of relativity in a 3D immersive environment (a CAVE: Cave Automatic Virtual Environment). The use of the immersive environment is underpinned by the development of dedicated learning scenarios created through a dialectic between VR-related computational constraints and cognitive constraints that include students' difficulties. Investigating student's understanding of relativistic situations (that involve relative speeds close to c) led to the typifying of a cognitive profile that governed the situations to be implemented into the CAVE and the associated learning scenarios