Although IL-4 is a well-characterized multi-functional cytokine, its role as a survival factor in T cells is not completely understood. In an attempt to uncover IL-4-mediated survival, we studied caspase activation in primary mouse T lymphocytes undergoing death by neglect, activation-induced or steroid-induced cell death. Here, we identify the executioner...
Dissolved silicic acid (Si(OH)4) and biogenic silica (BSiO2) concentrations were measured on four different cruises in the Southern Ocean along 1700 W from late October 1997 to mid-March 1998. These data were used to construct a vertically integrated Si budget in the surface layer from 58° to 68° S. Throughout...