Turkey to ask NATO for air defence missiles pointing at Syria

* Missiles to be used for defensive purposes - NATO chief * Heaviest bombardment in Damascus for 40 days - activists BRUSSELS, Nov 19 (Reuters) - Turkey is expected to formallyrequest on Monday that advanced NATO Patriot missiles be placedon its border to defend against Syrian attacks, Westernofficials said. Syrian rebels fighting President Bashar al-Assad have beenable to take large swathes of