Specific dose-response effects of TGF-beta1 on developmentally distinct hematopoietic stem/progenitor cells from human umbilical cord blood.

A device for confining oil floating upon the surface of a large body of water employs a horizontally deployable continuous pliable oil-resistant wall having parallel upper and lower edges. A multitude of uniformly spaced vertical support members are attached to the wall. A non-extendable cable engages the vertical support members in parallel relationship to the edges of the wall. Floatation devices are attached to the vertical support members adjacent the upper edge of the wall, and weight devices are attached to the vertical support members adjacent the lower edge of the wall. The effect of the flotation and weight devices is to cause the wall to ride vertically in the water with its upper edge extending above the oil level.