NEW YORK — Columbia University President Minouche Shafik resigned Wednesday after a brief, tumultuous tenure that saw the head of the prestigious New York university grapple with protests over the Israel-Hamas war and criticism over how the school handled divisions related to the conflict. [time-brightcove not-tgx=”true”] The Ivy League school in upper Manhattan was roiled this year by student protests, culminating in scenes of police officers carrying zip ties and riot shields storming a building that had been occupied by pro-Palestinian protesters.