one of a group of cells that develop in the walls of the seminiferous tubules. Spermatogenic cells include spermatogonia, spermatocytes, and spermatidsâall of which are transitional forms between primary sexual cells and spermatozoa.
long-haul optics. Long-haul optics refers to the transmission of visible light signals over optical fiber cable for great distances, especially without or with minimal use of repeaters. Normally, repeaters are necessary at intervals in a length of fiber optic cable to keep the signal quality from deteriorating to the point of non-usability. In long-haul optical systems, the goal is to minimize the number of repeaters per unit distance, and ideally, to render repeaters unnecessary.
A striking characteristic of the constructed US long-haul. ï¬ber-optic network is a signiï¬cant amount of observed in-. frastructure sharing. A qualitative assessment of the risk in-. herent in this observed sharing of the US long-haul ï¬ber-. optic infrastructure forms the second contribution of this pa-.