Mechanism of Action. Levocetirizine, the active enantiomer of cetirizine, is an anti histamine; its principal effects are mediated via selective inhibition of H1 receptors. The antihistaminic activity of levocetirizine has been documented in a variety of animal and human models. In vitro binding studies revealed that levocetirizine has an affinity for the human H1-receptor 2-fold higher than that of cetirizine (Ki = 3 nmol/L vs. 6 nmol/L, respectively).
The ice island, which is about half the height of the Empire State Building, is the biggest piece of ice to break away from the Arctic icecap since 1962 and amounts to a quarter of the Petermann 70-kilometer floating ice shelf, according to research leader Andreas Muenchow.
The Kutiah Glacier in Pakistan holds the record for the fastest glacial surge. In 1953, it raced more than 12 kilometers (7.5 miles) in three months, averaging about 112 meters (367 feet) per day. Satellite images caught this large iceberg, named A54, calving off of what remains of the Larsen Ice Shelf in Antarctica.