Changes in wood temperature under high-speed friction

Thermal effects at the surface of a sample wood specimen while it is rubbed by reduction with a metal disk rotating at high speed are investigated. The results provide fundamental data for the development of new surface processing methods. The results of high-speed friction tests showed that the wood surface developed high-temperature regions due to the effect of friction heat, and deformed tissue was observed at the wood surface in the region that experienced the rubbing action. The thermal effects extended to a deep range in the deformed region by reduction due to different fiber inclination angles, both parallel and normal to the friction surface. The thermal effects from the rubbed conditions of the reduction and feed speed also extended deeply into the region deformed by reduction, although the thermal effect was decreased at higher feed speed. From the results of these friction tests, the change in wood temperature is described unambiguously by factors related to pressure on the friction surface.     

Dependence of self-tolerance on TRAF6-directed development of thymic stroma

The microenvironments of the thymus are generated by thymic epithelial cells (TECs) and are essential for inducing immune self-tolerance or developing T cells. However, the molecular mechanisms that underlie the differentiation of TECs and thymic compartmentalization are not fully understood. Here we show that deficiency in the tumor necrosis factor receptor-associated factor (TRAF) 6 results in disorganized distribution of medullary TECs (mTECs) and the absence of mature mTECs. Engraftment of thymic stroma of TRAF6(-/-) embryos into athymic nude mice induced autoimmunity. Thus, TRAF6 directs the development of thymic stroma and represents a critical point of regulation for self-tolerance and autoimmunity.