The University of Vermont Fleming Museum of Art’s spring exhibitions, “Global Miniatures” and “Small Worlds: Miniatures in Contemporary Art,” explore how little things can make a big impact. In association with these exhibitions, lauded writer Lia Purpura reads and discusses her essay “On Miniatures,” in which she examines the allure of small-scale objects. The four-time Pushcart Prize-winning wordsmith, who has published four poetry collections and three essay collections, also lets lit lovers in on her upcoming book of essays, All the Fierce Tethers, due this month.