Yuki Matsuyama

Characterization of factors regulating lamina‐specific growth of thalamocortical axons

During development, most thalamocortical axons extend through the deep layers to terminate in layer 4 of neocortex. To elucidate the molecular mechanisms that underlie the formation of layer-specific thalamocortical projections, axon outgrowth from embryonic rat thalamus onto postnatal neocortical slices which had been fixed chemically was used as an experimental model system. When the thalamic explant was juxtaposed to the lateral edge of fixed cortical slice, thalamic axons extended farther in the deep layers than the upper layers. Correspondingly, thalamic axons entering from the ventricular side extended farther than those from the pial side. In contrast, axons from cortical explants cultured next to fixed cortical slices tended to grow nearly as well in the upper as in the deep layers. Biochemical aspects of lamina-specific thalamic axon growth were studied by applying several enzymatic treatments to the cortical slices prior to culturing. Phosphatidylinositol phospholipase C treatment increased elongation of thalamic axons in the upper layers without influencing growth in the deep layers. Neither chondroitinase, heparitinase, nor neuraminidase treatment influenced the overall projection pattern, although neuraminidase slightly decreased axonal elongation in the deep layers. These findings suggest that glycosylphosphatidylinositol-linked molecules in the cortex may contribute to the laminar specificity of thalamocortical projections by suppressing thalamic axon growth in the upper cortical layers.

Quantitative Design Modification for the Recyclability of Products

This paper proposes a design support method for increasing the recyclability of electrical and electronic products. The method estimates the recyclability rate and the disassembly time of a product based on its material composition and end-of-life scenario. Sensitivity analysis is conducted on the recyclability rate in order to quantify the impact of design changes in the product’s material composition, mass of components, and end-of-life treatment processes. For the feasibility check of the design changes, we introduce a structural model of the product, which represents the geometric constraints among components to assess their disassemblability. As a case study, the recyclability of a LCD TV with an end-of-life scenario in Europe was evaluated and sensitivity analysis on the TV generated design alternatives that increase the recyclability rate while keeping the disassembly time of the original design.

Consistency Management System Between Product Design and the Lifecycle

Within the framework of sustainability in manufacturing industry, product lifecycle design is a key approach for constructing resource circulation systems of industrial products that drastically reduce environmental loads, resource consumption and waste generation. In such design, designers should consider both a product and its lifecycle from a holistic viewpoint, because the product’s structure, geometry, and other attributes are closely coupled with the characteristics of the lifecycle. Although product lifecycle management (PLM) systems integrate product data during its lifecycle into one data architecture, they do not focus on support for lifecycle design process. In other words, PLM does not provide explicit models for designing product lifecycles. This paper proposes an integrated model of a product and its lifecycle and a method for managing consistency between the two. For the consistency management, three levels of consistency (i.e., topological, geometric, and semantic) are defined. Based on this management scheme, the product lifecycle model allows designers to evaluate environmental, economic, and other performance of the designed lifecycle using lifecycle simulation.© 2013 ASME

Proposal of Design Environment for Life Cycle Scenario

To reduce environmental impact and resource consumption, life cycle design is required; especially planning a strategy of product life cycle in the early design stage is needed. On the strategy planning, rationales of designer’s decision and design alternatives should be managed. This paper proposes a method of supporting for planning the strategy with representation scheme called life cycle scenario by managing design rationale and alternatives. We implemented a life cycle scenario description support system and verified the system by a case study.

1129 Axonal growth pattern of lateral geniculate nucleus neurons on fixed cortical slice

Vertebrate neural development is initiated during gastrulation by the inductive action of the Spemann’s organizer (presumptive dorsal mesoderm) on neighbouring ectoderm. We have previously shown that fibroblast growth factor (FGF) can mimic the action of the organizer to induce Xenopus ectoderm cells in culture to express position-specific neural markers along the anteroposterior axis and also that several Xenopus FGF receptor (XFGFR) genes are transcribed in gastrula ectoderm cells. To further elucidate whether these XFGFRs are involved in the neural induction in living organisms, detailed studies using the dominant-negative molecules for XFGFR were done by injecting m.RNAs of these molecules into early embryos. In the co-culture system with organizer cells/ectoderm cells, it is shown that blocking FGF-signalIing in ectoderm cells by overexpression of a dominant-negative form of XFGFR leads to disruption of the neural differentiation. Our findings indicate that FGF family member(s) are a promising candidate for the neural-inducing morphogen from the organizer.