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).
Glacier Calf That Broke Off Greenland's Jakobshavn Could Be Largest Ever. The Jakobshavn glacier-Greenland's fastest-moving glacier located near Ilulissat-is seen in a NASA image taken by the Operational Land Imager (OLI) on the Landsat 8 satellite August 16, 2015.
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.