Further, he urged filmmakers to refrain from producing movies that perpetuated negative stereotypes. Discrimination and racism against Israeli Ethiopians is still perpetuated. Once Silkies became more common in the West, many myths were perpetuated about them. Pop culture has perpetuated the "hillbilly" stereotype. This myth had been perpetuated after the release of people like John H. Noble. According to Schaefer, sexism is perpetuated by all major social institutions. The situation was perpetuated by real estate agents' continuing racial discrimination. This was all perpetuated by President Ulysses S. Grant's belief toward civilizing Indigenous cultures. Ideas of gender are thus perpetuated through globalization, leaving women vulnerable. Its existence can only be perpetuated by constant expansion. Dependency is perpetuated by using capitalism and finance. Landis perpetuated the color line and prolonged the segregation of organized baseball. Such special interests have perpetuated empire building throughout history. It was subsequently perpetuated among British schoolchildren. Galen perpetuated the tradition of Hippocratic medicine, making some advancements, but also some regressions.