Rendering and interactive virtual prototyping

Application of virtual reality techniques to architectural design allows to decrease the conception cost by virtual prototyping . In order to make the prototype usable for the decision process, an accurate lighting simulation must be done . The important need of interactivity in the manipulation of the prototype, for virtual walk-through or for modifying the prototype, implies a time efficient lighting simulation in the virtual world . Generaly, lighting simulation used in this type of application used empirical models whose only advantage is the real-time simulation . Texture mapping is a technique widely used to increase the quality of the simulation but without reaching the needed accuracy for architectural design . The radiosity model, based on the radiative transfers theory, allows to determine the lighting of a scene in a view-independent way. This model's limitation is its complexity. Also, its use in a virtual prototyping application needs the definition of adapted evaluation method . In this paper we propose a software environment, organised around two simulation kernels - Visualisation-interaction and Lighting simulation - that allows the use of the radiosity model during the design of an architectural environment. We present more precisely the design and the implementation of the lighting simulation module, called Eclairagiste, which objective is to ensure the maximum lighting accuracy at each instant . The Eclairagiste module, defined as an entity of the virtual reality programming environment VIPER, uses a multi-resolution representation of the radiosity function and relie on resolution method derived from hierarchical radiosity.L'application des techniques de réalité virtuelle à l'architecture permet de diminuer les coûts de conception du projet par prototypage virtuel. Afin de rendre le prototype développé exploitable pour la prise de décision, une simulation convenable de l'éclairage doit être effectuée. Le besoin important d'interactivité dans la manipulation du prototype, soit pour des déplacements de l'utilisateur dans le monde virtuel, soit pour des modifications géométriques apportées à ce monde, nécessite un éclairage très rapide de la scène. Actuellement, les modèles d'éclairage utilisés, dans ce type d'application, sont des approximations empiriques des modèles physiques dont le seul avantage est la rapidité d'évaluation. Les textures sont largement utilisées pour augmenter le réalisme des scènes virtuelles mais le niveau de simulation de l'éclairage reste grossier. Le modèle de radiosité, modèle physique fondé sur l'évaluation des transferts radiatifs dans une scène, permet de déterminer, de façon indépendante du point de vue, la valeur du signal lumineux en tout point de la scène, en tenant compte de toute la scène (illumination globale). Le principal inconvénient de ce modèle étant le temps de calcul nécessaire à sa résolution, son utilisation dans une application de prototypage passe par la définition de techniques de résolution adaptées. Nous proposons dans cet article une plate-forme logicielle, organisée autour de deux noyaux de simulation - Visualisation-Interaction et Simulation de l'éclairage -, permettant d'utiliser le modèle de radiosité lors de la conception par prototypage virtuel d'environnements architecturaux. Nous présentons plus particulièrement la conception et l'implantation d'un module de simulation de l'éclairage, appelé éclairagiste, dont l'objectif est d'assurer le réalisme maximum à chaque instant. Le module éclairagiste, définit comme une entité de l'environnement de programmation d'applications de réalité virtuelle VIPER, utilise une modélisation multi-échelle de la radiosité et repose sur une méthode de résolution dérivée de la radiosité hiérarchique

Simultaneous removal of CO2, SO2, and NOx from flue gas by liquid phase dehumidification at cryogenic temperatures and low pressure

Published versio

A Novel Mouse c-fos Intronic Promoter That Responds to CREB and AP-1 Is Developmentally Regulated In Vivo

BACKGROUND: The c-fos proto-oncogene is an archetype for rapid and integrative transcriptional activation. Innumerable studies have focused on the canonical promoter, located upstream from the transcriptional start site. However, several regulatory sequences have been found in the first intron. METHODOLOGY/PRINCIPAL FINDINGS: Here we describe an extremely conserved region in c-fos first intron that contains a putative TATA box, and functional TRE and CRE sites. This fragment drives reporter gene activation in fibroblasts, which is enhanced by increasing intracellular calcium and cAMP and by cotransfection of CREB or c-Fos/c-Jun expression vectors. We produced transgenic mice expressing a lacZ reporter controlled by the intronic promoter. Lac Z expression of this promoter is restricted to the developing central nervous system (CNS) and the mesenchyme of developing mammary buds in embryos 12.5 days post-conception, and to brain tissue in adults. RT-QPCR analysis of tissue mRNA, including the anlage of the mammary gland and the CNS, confirms the existence of a novel, nested mRNA initiated in the first intron. CONCLUSIONS/SIGNIFICANCE: Our results provide evidence for a novel, developmentally regulated promoter in the first intron of the c-fos gene

Meta-analysis: Neither quick nor easy

BACKGROUND: Meta-analysis is often considered to be a simple way to summarize the existing literature. In this paper we describe how a meta-analysis resembles a conventional study, requiring a written protocol with design elements that parallel those of a record review. METHODS: The paper provides a structure for creating a meta-analysis protocol. Some guidelines for measurement of the quality of papers are given. A brief overview of statistical considerations is included. Four papers are reviewed as examples. The examples generally followed the guidelines we specify in reporting the studies and results, but in some of the papers there was insufficient information on the meta-analysis process. CONCLUSIONS: Meta-analysis can be a very useful method to summarize data across many studies, but it requires careful thought, planning and implementation

Evaluating the role of quality assessment of primary studies in systematic reviews of cancer practice guidelines

BACKGROUND: The purpose of this study was to evaluate the role of study quality assessment of primary studies in cancer practice guidelines. METHODS: Reliable and valid study quality assessment scales were sought and applied to published reports of trials included in systematic reviews of cancer guidelines. Sensitivity analyses were performed to evaluate the relationship between quality scores and pooled odds ratios (OR) for mortality and need for blood transfusion. RESULTS: Results found that that whether trials were classified as high or low quality depended on the scale used to assess them. Although the results of the sensitivity analyses found some variation in the ORs observed, the confidence intervals (CIs) of the pooled effects from each of the analyses of high quality trials overlapped with the CI of the pooled odds of all trials. Quality score was not predictive of pooled ORs studied here. CONCLUSIONS: Had sensitivity analyses based on study quality been conducted prospectively, it is highly unlikely that different conclusions would have been found or that different clinical recommendations would have emerged in the guidelines

Heterozygous Mutation of Drosophila Opa1 Causes the Development of Multiple Organ Abnormalities in an Age-Dependent and Organ-Specific Manner

Optic Atrophy 1 (OPA1) is a ubiquitously expressed dynamin-like GTPase in the inner mitochondrial membrane. It plays important roles in mitochondrial fusion, apoptosis, reactive oxygen species (ROS) and ATP production. Mutations of OPA1 result in autosomal dominant optic atrophy (DOA). The molecular mechanisms by which link OPA1 mutations and DOA are not fully understood. Recently, we created a Drosophila model to study the pathogenesis of optic atrophy. Heterozygous mutation of Drosophila OPA1 (dOpa1) by P-element insertion results in no obvious morphological abnormalities, whereas homozygous mutation is embryonic lethal. In eye-specific somatic clones, homozygous mutation of dOpa1 causes rough (mispatterning) and glossy (decreased lens deposition) eye phenotypes in adult Drosophila. In humans, heterozygous mutations in OPA1 have been associated with mitochondrial dysfunction, which is predicted to affect multiple organs. In this study, we demonstrated that heterozygous dOpa1 mutation perturbs the visual function and an ERG profile of the Drosophila compound eye. We independently showed that antioxidants delayed the onset of mutant phenotypes in ERG and improved larval vision function in phototaxis assay. Furthermore, heterozygous dOpa1 mutation also caused decreased heart rate, increased heart arrhythmia, and poor tolerance to stress induced by electrical pacing. However, antioxidants had no effects on the dysfunctional heart of heterozygous dOpa1 mutants. Under stress, heterozygous dOpa1 mutations caused reduced escape response, suggesting abnormal function of the skeletal muscles. Our results suggest that heterozygous mutation of dOpa1 shows organ-specific pathogenesis and is associated with multiple organ abnormalities in an age-dependent and organ-specific manner

Transcriptomic analysis of milk somatic cells in mastitis resistant and susceptible sheep upon challenge with Staphylococcus epidermidis and Staphylococcus aureus

<p>Abstract</p> <p>Background</p> <p>The existence of a genetic basis for host responses to bacterial intramammary infections has been widely documented, but the underlying mechanisms and the genes are still largely unknown. Previously, two divergent lines of sheep selected for high/low milk somatic cell scores have been shown to be respectively susceptible and resistant to intramammary infections by <it>Staphylococcus spp</it>. Transcriptional profiling with an 15K ovine-specific microarray of the milk somatic cells of susceptible and resistant sheep infected successively by <it>S. epidermidis </it>and <it>S. aureus </it>was performed in order to enhance our understanding of the molecular and cellular events associated with mastitis resistance.</p> <p>Results</p> <p>The bacteriological titre was lower in the resistant than in the susceptible animals in the 48 hours following inoculation, although milk somatic cell concentration was similar. Gene expression was analysed in milk somatic cells, mainly represented by neutrophils, collected 12 hours post-challenge. A high number of differentially expressed genes between the two challenges indicated that more T cells are recruited upon inoculation by <it>S. aureus </it>than <it>S. epidermidis</it>. A total of 52 genes were significantly differentially expressed between the resistant and susceptible animals. Further Gene Ontology analysis indicated that differentially expressed genes were associated with immune and inflammatory responses, leukocyte adhesion, cell migration, and signal transduction. Close biological relationships could be established between most genes using gene network analysis. Furthermore, gene expression suggests that the cell turn-over, as a consequence of apoptosis/granulopoiesis, may be enhanced in the resistant line when compared to the susceptible line.</p> <p>Conclusions</p> <p>Gene profiling in resistant and susceptible lines has provided good candidates for mapping the biological pathways and genes underlying genetically determined resistance and susceptibility towards <it>Staphylococcus </it>infections, and opens new fields for further investigation.</p