Generate a topic word for the given sentence. A topic word is usually the name of a person, place, animal, concept or object the sentence is focusing on.

the duke lemur center is an 85 acre sanctuary for several species of lemurs and lorises.
duke lemur center

the temple of athena nike is a temple on the acropolis of athens.
temple of athena nike

gammaproteobacteria are a large group of bacteria.

gammaproteobacteria