Mammary gland gestation, serum progesterone remains at a stably high concentration so signaling through its receptor is continuously activated. As one of the transcribed genes, Wnts secreted from mammary epithelial cells act paracrinely to induce more neighboring cells' branching. When the lactiferous duct tree is almost ready, "leaves" alveoli are differentiated from luminal epithelial cells and added at the end of each branch. In late pregnancy and for the first few days after giving birth, colostrum is secreted. Milk secretion (lactation) begins a few days later due to reduction in circulating progesterone and the presence of another important hormone prolactin, which mediates
The World Is What It Is The World Is What It Is The World Is What It Is: The Authorized Biography of V. S. Naipaul is a biography of the Nobel Prize-winning author V. S. Naipaul by Patrick French. It was published in 2008 (by Picador in the UK and Knopf in the USA). The title is a quotation from Naipaul's book "A Bend in the River". "The world is what it is; men who are nothing, who allow themselves to become nothing, have no place in it." French deals with Naipaul's family background and his life from his birth in 1932 until his second marriage