Kathryn Niles, who teaches at Binghamton University, and Tess Zizak, a BFA candidate at BU, are showing “Transience and Continuance,” featuring transient images by Niles, such as the “End of Season Milkweed” with pods and fall leaves. Zizak works primarily in landscape paintings, both watercolor and oil, as well as pen-and-ink drawings of trees.