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 region, which borders the Sahara, is not a true desert but may become one as the Sahara advances southward. Arid lands on the edge of the Sahara in the Horn of Africa, such as the Ogaden Desert, consume portions of Eritrea, Ethiopia, Kenya, Somalia and the Sudan. Egypt's Nubian Desert and Ethiopia's Danakil Desert are also arid environments that might soon become Africa's next big desert. National Geographic: Desert Profile.