Geographer Looks Back at Human History to Understand How We Got to 7 Billion and Counting

Environmental geographer Ruth DeFries is a pioneer in the study of how humans have transformed the surface of the Earth. Using satellite data, she explores how changes in Earth’s vegetation can affect climate, ecosystems and the relative ability of humans and other species to survive on this planet.

Her new book, The Big Ratchet: How Humanity Thrives in the Face of Natural Crisis, takes the very long view of human history, describing how, for at least 10,000 years, we have continually created new technologies that have allowed our numbers to grow.


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Medical Center researchers have identified the immune cells responsible for destroying hair follicles in people with alopecia areata, a common autoimmune disease that causes hair loss.


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Elizabeth Hillman, associate professor of biomedical engineering, leads a team that is developing new imaging methods for the living brain. Their goal is to understand the way that the brain functions and regulates its blood flow, which can provide important clues to understanding early brain development, disease and aging.