We defined the RDR as the number of roots that penetrated the lower part of the mesh (i.e., ≥50° from the horizontal, centered on the stem) divided by the total number of roots that penetrated the whole mesh.
Examination of the disc data indicated that a better relationship between wood density and height-within-stem would be obtained if density was predicted using relative height (i.e. the height of a disc in the stem divided by total stem length, (disc height)/ tree height)) rather than absolute height.
The advent of bibliometrics (as a consequence of the journal impact factor) led to what is commonly recognised as the Stem/non-Stem divide – whereby those disciplines that publish at a more frequent rate, and in journals rather than books or monographs, tend to have a better coverage.
This trend, based on 2011 data from the National Science Foundation's Survey of Earned Doctorates, also helps explain why gender ratios don't follow the simplified STEM/non-STEM divide in some fields, including philosophy and biology, they conclude.
The radial glia act as stem cells, dividing to produce immature nerve cells which climb onto their mother cell's radially aligned fibre and then crawl along it, with amoeba-like movements, towards the tube's outer surface.
Cancer is rare in the small intestinal epithelium, which is surprising since this tissue represents a large mass with many stem cells dividing many times.
A group at the Whitehead Institute for Biomedical Research in Cambridge, Massachusetts, stumbled upon PrP as they searched for ways to keep their stem cells dividing in the lab.
The cells of the V lineage act as stem cells, dividing asymmetrically at each of the subsequent larval stages (L2 L4).
Stem cells divide slowly and generate transit-amplifying progenitor cells which divide rapidly to produce neuroblasts [4], [5].
The stem cells divide and sometimes specialize into other types of "intermediate" stem cells that in turn divide and form the neurons that make up brain tissue.
