No abstract

Architecture and applications of a massively parallel processor are described. Volumes of 256×256×128 voxels can be visualized at a frame rate of 10 Hz using volume oriented visualization algorithms. A prototype of the scalable and modular system is currently set up. 3D rotation around an arbitrary rotation axis, perspective, zooming, and arbitrary gray value mapping are provided in real-time. Multi-user access over high-speed networks is possible. A volume oriented visualization algorithm is used that is tailored to the requirements in medicine [5]. With this algorithm, small structures of a size down to the pixel resolution, and structures without defined surfaces can be visualized as well as semi-transparent objects. One application of the system is therapy planning in heart surgery.

No abstract

There is evidence that the proliferation of cells is controlled by the number of divisions after leaving a multi-potent (stem) cell. A detailed study of the growth of tissue in the small intestinal tract, more precisely the growth of crypts and villi, suggests that not only the proliferation but also the differentiation of cells obey the same biological law. We postulate a theory of a cellular internal control mechanism: the cell-generation control of differentiation and proliferation. This basic mechanism, together with external influences, determines the kinetic behaviour of the crypt-villus system.