1 Aden, Yemen is at 12 49'N, 45 1'E, 3 m (10 ft). 2  See map. 3  Aden has a subtropical desert / low-latitude arid hot climate (K ppen-Geiger classification: BWh). 4  The annual average temperature is 29.2 degrees Celsius (84.5 degrees Fahrenheit).
The core of a sphingolipid is an amino alcohol called sphingosine. Complex sphingolipids located in the plasma membrane of animal cells (especially nerve cells) have a structural function and are believed to protect the cell surface from harmful environmental factors.
Surfactant protein A (SP-A) is the major protein component of pulmonary surfactant, a material secreted by the alveolar type II cell that reduces surface tension at the alveolar airâliquid interface.urfactant protein A has been shown to regulate the homeostasis of surfactant phospholipids, facilitate the lowering of surface tension in the alveolus, and prevent the inhibition of surfactant function by plasma proteins.