The White House today holds 142 rooms on six floors, the floor space totaling approximately 55,000 square feet. It has hosted longstanding traditions such as the annual Easter Egg Roll, as well as historic events like the 1987 nuclear arms treaty with Russia.
This parameterization is based on the topological definition of a MÃ¶bius strip as the rotation of a line segment around a circle, with half twist. a is the radius of the circle about which the line is rotated, u is the angular position around the circle of the segment, and v is the position along the horizontal line.
In birds, the bursa of Fabricius (Latin: Bursa cloacalis or Bursa fabricii) is the site of hematopoiesis, a specialized organ that, as first demonstrated by Bruce Glick and later by Max Cooper and Robert Good, is necessary for B cell (part of the immune system) development in birds.ammals generally do not have an equivalent organ; the bone marrow is often both the site of hematopoiesis and B cell development. The bursa is present in the cloaca of birds and is named after Hieronymus Fabricius who described it in 1621.