Madeline McIntosh, who was named president of the Penguin Publishing Group last September, put her own stamp on the division last week, shifting the responsibilities of a number of high-ranking editors and publishers, eliminating the positions of two other top executives, and closing the Hudson Street Press and Gotham Books imprints.The most significant shift came at Viking, where longtime president Clare Ferraro was replaced by a new team led by Brian Tart, who had been president and publisher of Dutton, Gotham, and Avery. Tart was named Viking president and publisher, and McIntosh brought in Andrea Schulz as Viking v-p and editor-in-chief. Schulz was previously editor-in-chief at Houghton Mifflin Harcourt. Kate Stark, head of marketing at Riverhead and Putnam, joined Viking as associate publisher and director of marketing and will retain her Riverhead duties, while relinquishing her Putnam responsibilities.