sentences:  His 1989 book "Death by Migration" combined medical and population history, tracing the effects of tropical diseases on Europeans in tropical Africa during the time before medicines were available to treat these conditions effectively.A controversial opinion piece published in a 1995 issue of "The Chronicle of Higher Education" titled "Ghettoizing African History" criticized the frequent equation of African and African American scholars in college and university departments of history with jobs concerning the history of Africa.Although Curtin mentioned that this practice might discourage some caucasian academicians from specializing in African studies, his comments were also an argument for more opportunities for African-American scholars.