The test may cause momentary gagging because the back of the throat is a sensitive area, but it should not be painful. The sample your doctor collects is taken to a laboratory, where it is put on a plate that allows any bacteria on it to grow. This process is called a culture.
Often these are called transition zones which represent the start and end of a specific region and can be large or small. For example, the transition zone between Sub-Saharan Africa and North Africa is rather large because there is a mixing between the two regions. Regional geographers study this zone as well as the distinct characteristics of Sub-Saharan Africa and North Africa.
The Sahel, in particular, will face the most extreme challenges, compounded by the threat of the Al-Qaeda in the Islamic Maghreb. The Arabic word sahel (shore) denotes the transition zone between the Sahara Desert to the north and the savannah plains to the south. It is a semiarid region with an average rainfall between 12 to 20 inches per year. Since the definition of the Sahel is based on climate, it does not abide by strict international borders.