On this edition of our show, we speak with Steve McDonald, an artist and illustrator from Canada, about his new book, "Fantastic Cities: A Coloring Book of Amazing Places Real and Imagined." It's a striking collection of highly detailed line drawings depicting aerial views of real cities from around the world, both genuine and fictional. From New York, London, and Paris, to Istanbul, Tokyo, and Amsterdam, this large-format "coloring book for adults" combines arresting cityscapes with rather mind-bending and/or kaleidoscope-like close-ups of architectural details of all sorts. McDonald tells us how he chose and created these particular images, and he also speaks more generally about the growing trend -- found in cultures all over the globe -- to employ coloring books as a form of stress management, mental focusing, or even meditation. Also on this edition of ST, our commentator John Schumann offers a short piece on Theranos, a health-tech and medical-services start-up based in Palo Alto, California, that has encountered much controversy lately. As was noted a few days ago in The New York Times: "A Silicon Valley story with intoxicating appeal, Theranos by some measures has a $9 billion valuation because, in part, of its claims that its proprietary technology has the potential to disrupt the established players in health care. Its protagonist was inspiring. Ms. [Elizabeth] Holmes, a young Stanford University dropout who speaks Mandarin, applied for her first patent before she was 20 and fearlessly commanded any room she entered. Her board was populated with former diplomats and leaders of the Senate. But an investigation published in The Wall Street Journal in October changed the narrative by raising serious concerns about whether the company's technology actually works. Now, after a surprise inspection last summer, the Food and Drug Administration is requiring that Theranos's equipment and individual tests go through the regulatory process and get approval. This will determine whether its foundational technology is a reality or...an unfulfilled grand promise."