Generating adaptive immunity after infection or immunization requires physical interactions within a lymph node (LN) T-zone between antigen-bearing dendritic cells (DCs) that arrive from peripheral tissues and rare cognate T cells entering via high endothelial venules (HEVs). This interaction results in activation of cognate T cells, expansion of that T cell lineage and their exit from the LN T zone via efferent lymphatics (ELs). How antigen-specific T cells locate DCs within this complex environment is controversial, and both random T cell migration and chemotaxis have been proposed. We developed an agent-based computational model of a LN that captures many features of T cell and DC dynamics observed by two-photon microscopy. Our simulations matched in vivo two-photon microscopy data regarding T cell speed, short-term directional persistence of motion and cell motility. We also obtained in vivo data regarding density of T cells and DCs within a LN and matched our model environment to measurements of the distance from HEVs to ELs. We used our model to compare chemotaxis with random motion and showed that chemotaxis increased total number of T cell DC contacts, but decreased unique contacts, producing fewer activated T cells. Our results suggest that, within a LN T-zone, a random search strategy is optimal for a rare cognate T cell to find its DC match and maximize production of activated T cells. KeywordsAgent-based computational model; T cell repertoire scanning; two-photon microscopy; lymph node model

Integration of the Rapid Prototyping environmental aspects: first focus on the electrical energy consumption. Design/methodology/approach Various manufacturing parameters have been tested on three rapid prototyping systems: Thermojet (3DS), FDM 3000 (Stratasys) and EOSINT M250 Xtended (EOS). The objective is to select sets of parameters for reduction of electrical energy consumption. For this, we have manufactured a part in several orientations and positions in the chamber of these RP systems. For each test, we noted the electrical power. Finally, we propose certain rules to minimize this electrical energy consumption during a job. Findings It is important to minimize the manufacturing time but there is no general rule for optimization of electrical energy consumption. Each RP system must be tested with energy consumption considerations under the spotlight. Research limitations/implications Our work is only based on Rapid Prototyping processes. Our objective is to take into consideration the complete life-cycle of an rapid prototyped part: manufacturing of raw material as far as reprocessing of waste. Practical implications To decrease electrical energy consumption for a job What is original/value of paper The environmental aspects are not studied as well as in rapid prototyping.

A functioning immune system and the process of antigen presentation in particular encompass events that occur at multiple length and time scales. Despite a wealth of information in the biological literature regarding each of these scales, no single representation synthesizing this information into a model of the overall immune response as it depends on antigen presentation is available. In this article, we outline an approach for integrating information over relevant biological and temporal scales to generate such a representation for major histocompatibility complex class II-mediated antigen presentation. In addition, we begin to address how such models can be used to answer questions about mechanisms of infection and new strategies for treatment and vaccines.

Proceeding to 21st CIRP Conference on Life Cycle EngineeringConsidering the potential for new product design possibilities and the reduction of environmental impacts, Additive Manufacturing (AM) processes are considered to possess significant advantages for automotive, aerospace and medical equipment industries. One of the commercial AM techniques is Binder-Jetting (BJ). This technique can be used to process a variety of materials including stainless steel, ceramic, polymer and glass. However, there is very limited research about this AM technology on sustainability aspect. This paper presents a method to build an energy consumption model for printing stage of BJ process. Mathematical analyses are performed to find out the correlation between the energy consumption and geometry of the manufactured part. Based on the analyses, total energy consumption is calculated as a function of part geometry and printing parameters. Finally, test printing is performed to check the accuracy of the model. This process model provides a tool to optimize part geometry design with respect to energy consumption.International audienceConsidering the potential for new product design possibilities and the reduction of environmental impacts, Additive Manufacturing (AM) processes are considered to possess significant advantages for automotive, aerospace and medical equipment industries. One of the commercial AM techniques is Binder-Jetting (BJ). This technique can be used to process a variety of materials including stainless steel, ceramic, polymer and glass. However, there is very limited research about this AM technology on sustainability aspect. This paper presents a method to build an energy consumption model for printing stage of BJ process. Mathematical analyses are performed to find out the correlation between the energy consumption and geometry of the manufactured part. Based on the analyses, total energy consumption is calculated as a function of part geometry and printing parameters. Finally, test printing is performed to check the accuracy of the model. This process model provides a tool to optimize part geometry design with respect to energy consumption

In a one-variable, finite size reaction-diffusion system, the existence of a minimal domain size required for the existence of a non-zero steady state is predicted, provided that the reaction-diffusion variable has a fixed value of zero at the boundaries of the domain (Dirichlet boundary conditions). This type of reaction diffusion model can be applied in population biology, in which the finite domain of the system represents a refuge where individuals can live normally immersed in a desert, or region where the conditions are so unfavourable that individuals cannot live in it. Building on a suggestion by Kenkre and Kuperman, and using non-chemotactic E. coli populations and a quasi-one-dimensional experimental design, we were able to find a minimal size (approximately 0.8 cm) for a refuge immersed in a region irradiated with intense UV light. The observed minimal size is in reasonable agreement with theory.

Originally developed for high-tech applications in the aeronautic and aerospace industry, carbon/epoxy composites have been increasingly used in the automotive, leisure, and sports industries for several years. Nevertheless, the carbon reinforcement is an expensive constituent, and it has been recently shown that it is also the most environmentally impacting in a composite part manufacturing. Recycling these materials (even restricted to the reinforcement recovery) could lead to economic and environmental benefits, while satisfying legislative end-oflife requirements. The solvolysis of the matrix by water under supercritical conditions is an efficient solution to recover the carbon fiber reinforcement with mechanical properties closed to the ones of virgin fibers. This paper aims at demonstrating the environmental feasibility of the recycling of carbon fiber/thermoset matrix composites by solvolysis of the matrix in supercritical water. This demonstration is based on life cycle assessment that evaluates benefits and environmental challenges of this recycling loop.

Considering the potential for new product design possibilities and the reduction of environmental impacts, Additive Manufacturing (AM) processes are considered to possess significant advantages for automotive, aerospace and medical equipment industries. One of the commercial AM techniques is Binder-Jetting (BJ). This technique can be used to process a variety of materials

The use of composite material increases. End of life regulations, material consumption reductions or restrictions, ask engineers about their potential use. Innovative recycling solutions arise that recover efficiently carbon fibres. This paper explores the design for composites recycling issue. Recycler becomes a new knowledge expert for the designer. It is necessary to analyze their information shares and exchanges. The recycler is an end of life facilitator. He is also the second life material user and can ask for material evolutions. The collaboration must be improved using knowledge performance indicators. These discussions will be enlightened by examples from carbon recycling experiments.