Calcium regulates the proliferation and differentiation of keratinocytes both in vivo and in vitro. Elevated extracellular Ca2+ concentration ([Ca2+](o)) raises the intracellular free calcium ([Ca2+](i)) and activates differentiation-related genes. Cells lacking the calcium-sensing receptor (CaR) fail to respond to [Ca2+](o) and to differentiate, indicating a role for CaR in keratinocyte differentiation. These concepts derived from in vitro experiments have been tested and confirmed in two mouse models. (C) 2003 Elsevier Ltd. All rights reserved.

As part of the ongoing international DECOVALEX project, four research teams used five different models to simulate coupled thermal, hydrological, and mechanical (THM) processes near underground waste emplacement drifts. The simulations were conducted for two generic repository types, one with open and the other with back-filled repository drifts, under higher and lower post-closure temperature, respectively. In the completed first model inception phase of the project, a good agreement was achieved between the research teams in calculating THM responses for both repository types, although some disagreement in hydrological responses are currently being resolved. Good agreement in the basic thermal-mechanical responses was also achieved for both repository types, even though some teams used relatively simplified thermal-elastic heat-conduction models that neglect complex near-field thermal-hydrological processes. The good agreement between the complex and simplified process models indicates that the basic thermal-mechanical responses can be predicted with a relatively high confidence level.