MRSA Definition and Symptoms. MRSA, methicillin-resistant staphylococcus aureus, is an infection that is caused by a certain strain of staph bacteria that is resistant to the commonly used antibiotics.
The Sahel (/sÉËhÉl/) is the ecoclimatic and biogeographic zone of transition in Africa between the Sahara Desert to the north and the Sudanian Savanna to the south. Having a semi-arid climate, it stretches across the south-central latitudes of Northern Africa between the Atlantic Ocean and the Red Sea.
The Sahel is also a cultural transition zone separating the Arab and Muslim dominated countries of North Africa from the African and Christian (and/or animist) peoples of sub-Saharan Africa.Note how the presence of Islam tails off dramatically as one leaves the Sahel and enters sub-Saharan Africa.he East African Rift Valley System is an example of a fissure in the Earthâs crust in which the continent is splitting apart, causing an extensive series of valleys, fingerlike freshwater lakes and volcanoes to form. The map below shows how dominant savanna zones are in sub-Saharan Africa, in particular the Sahel.