An Agent Based Architecture ForComponent-Based Software Development

Today\u27s companies are facing major changes in their organizations due to the changing environment in which they operate. They have to decrease the costs, decrease time to market, and improve quality. These imperatives have led to changes in the placement and role of IS department in the organization (Fried, 1995). Together with the recent advances in communication technology and powerful workstations, end-users have become more involved with the application development. Besides, the business processes change so fast that the traditional SDLC is too slow to keep up with these fluctuating requirements in the application domain. The need for rapid application development to respond to users\u27 changing needs, among the other mentioned trends, encourages the use of reusable software components. In (ATP, 1995), it is stated that at the level of vertical-market products, software design costs are generally $1 million to$10 million with near zero cost of reproducing additional units, and the typical production quantity is one. Reusable software components help organizations recover costs, improve quality through specialization, and develop rapidly from existing components

Determination Of The Features Of Instructional Computer Games

The ultimate goal of computer based education is to design an education-application which interactively presents all the relevant information in the best possible way. Imagine an expert systemwith all the advanced capabilities presents the information by using all sorts of different media, including virtual reality, accesses a rich knowledgebase, and interacts with students as an expert in the field. This kind of a system would provide the knowledge and experience of the best teacher to a large group of people. Today, the use of computers in education is generally an effort to imitate the conventional education by using the computer. But it may be necessary to adapt a totally different approach in order to fully utilize the capabilities of a computer. One of the best ways to utilize the power of the computers in education may be to present the instructional material in the form of an instructional computer game. Computer games can enhance learning while affecting the motivation and retention of knowledge and skills positively. In the context of this paper, learning is defined as enhancing the learning outcomes proposed by Gagné (1985). A game becomes an intentional education tool when the rules which govern the play of the game demand the development and use of educationally valuable skills, the acquisition of important knowledge, or exploration of a worthwhile world of experience

Chitin-based Materials in Tissue Engineering: Applications in Soft Tissue and Epithelial Organ

Chitin-based materials and their derivatives are receiving increased attention in tissue engineering because of their unique and appealing biological properties. In this review, we summarize the biomedical potential of chitin-based materials, specifically focusing on chitosan, in tissue engineering approaches for epithelial and soft tissues. Both types of tissues play an important role in supporting anatomical structures and physiological functions. Because of the attractive features of chitin-based materials, many characteristics beneficial to tissue regeneration including the preservation of cellular phenotype, binding and enhancement of bioactive factors, control of gene expression, and synthesis and deposition of tissue-specific extracellular matrix are well-regulated by chitin-based scaffolds. These scaffolds can be used in repairing body surface linings, reconstructing tissue structures, regenerating connective tissue, and supporting nerve and vascular growth and connection. The novel use of these scaffolds in promoting the regeneration of various tissues originating from the epithelium and soft tissue demonstrates that these chitin-based materials have versatile properties and functionality and serve as promising substrates for a great number of future applications

Ingénierie tissulaire de la muqueuse orale humaine

L’ingénierie de la muqueuse orale humaine (MOH) a pour but le comblement des pertes de substances suite à un traumatisme facial ou à la chirurgie des lésions malignes. Elle a aussi des applications en recherche pour élucider les mécanismes biologiques de la MO et en pharmacotoxicologie comme alternative à l’expérimentation animale. L'objectif de cette thèse était de reconstruire une MOH proche du tissu normal. À cette fin, la faisabilité du concept a d'abord été testée par co-culture de fibroblastes de la lamina propria et de cellules épithéliales de MOH dans le substrat de collagène-chitosan glycosaminoglycane, développé pour la production de peaux reconstruites. La caractérisation de la MOH reconstruite par histologie, immunohistochimie et microscopie électronique à transmission a montré la présence d’une LP équivalente avec un épithélium pluristratifié et non kératinisé très proche du tissu d’origine. Grâce à ce modèle, nous avons ensuite démontré que l’origine des fibroblastes (MO, cornée, peau) influence significativement l’épaisseur et l’ultrastructure de l'épithélium obtenu par culture de cellules épithéliales orales. Enfin, afin d'améliorer les propriétés adhésives du substrat à base collagène, nous avons ajouté au collagène, une élastine-like recombinante (ELR) contenant le tri-peptide d’adhésion cellulaire, RGD, et produit un nouveau substrat bicouche, poreux par lyophilisation et recouvert d’une couche fibreuse par électrofilage. Ces substrats ont été caractérisés par porosimétrie au mercure, microscopie électronique à balayage et essais mécaniques. Nous avons démontré l’effet stimulant de ELR sur la prolifération des fibroblastes et des cellules épithélialesTissue engineered human oral mucosa has the potential to fill tissue deficits caused by facial trauma or malignant lesion surgery. It can also help elucidate the biology of oral mucosa and serve as an alternative to in vivo testing of oral care products. The aim of this thesis was to construct a tissue engineered full-thickness human oral mucosa closely mimicking the native tissue. To this end, the feasibility of the concept was tested by co-culturing fibroblasts and epithelial cells isolated from normal human oral mucosa biopsies in a collagen-glycosaminoglycan-chitosan scaffold, developed in our laboratory to construct a skin equivalent. An oral mucosal equivalent closely mimicking the native one was obtained and characterized by histology, immunohistochemistry and transmission electron microscopy. Using the same model, the influence of mesenchymal cells on oral epithelial development was investigated by culturing epithelial cells on lamina propria, corneal stroma and dermal equivalents. They were found to significantly influence the thickness and the ultrastructure of the epithelium. Finally, in order to improve the adhesiveness of conventional scaffolds, an elastin-like recombinamer (ELR) containing the cell adhesion tripeptide, RGD, was used in the production of novel bilayer scaffolds employing lyophilization and electrospinning. These scaffolds were characterized by mercury porosimetry, scanning electron microscopy and mechanical testing. In vitro tests revealed positive contribution of ELR on the proliferation of both fibroblasts and epithelial cells. It was thus possible to construct a viable oral mucosa equivalent using the principles of tissue engineerin