Dissecting Empathy

For Green, a specialist in the philosophy of mind and the philosophy of language, empathy is a natural subject. According to recent theories put forth by evolutionary psychologists, empathy is not just a nice emotion but a necessary one. These psychologists believe that the ability to feel empathy confers a distinct evolutionary advantage. People who feel empathy are more likely to act in groups—and groups of people who combine their resources are more likely to pass on their genes than are individuals.

Empathy has also emerged as an important topic in neuroscience, where researchers have located an area of the brain that may be responsible for our ability to feel empathy. Among other things, this mirror neuron system allows us to partake in emotions that we observe in others. Recent studies of children with autism suggest that their mirror neuron system is weak.

For these investigations to advance, scientists must have a precise understanding of what they mean by empathy—and Green is working to characterize it. "Understanding empathy provides the basis for a more complex view of human communication. Empathetic communication requires active engagement and effort," says Green. "You feel with another person when you feel empathy."

Green is also interested in the role that the arts play in promoting empathy. "The arts can show us how an emotion or mood feels," he says. "Music that is eloquent and full of grief can let us know how grief feels."

Reversing Type 1 Diabetes

Jerry Nadler

The human body can be surprisingly resilient. In Type 1 diabetes, the body’s autoimmune system destroys insulin-producing beta cells in the pancreas, but, as scientists have recently discovered, the body soldiers on. For decades after the onset of the disease, it replaces the destroyed cells with new ones in a futile attempt to restore insulin production.

Jerry Nadler and his colleagues at the University of Virginia Health System have found a way to break this deadlock. With funding from the Ella Fitzgerald Charitable Foundation, the George Foundation and the National Institutes of Health, they administered a two-drug combination, lisofylline (LSF) and exendin-4 (Ex-4), to laboratory mice with Type 1 diabetes. LSF selectively suppresses parts of the immune system that target the beta cells and encourages beta cells to produce insulin, even in the presence of substances that cause inflammation. Ex-4 increases insulin secretion and helps beta cells grow.

"Our goal was to develop proof of concept," Nadler says. "Our team, which included Dr. Zandong Yang, was able to demonstrate for the first time that this combination of therapies could reverse the course of Type 1 diabetes."

Equally startling was the fact that the mice’s blood sugar level was still normal when the experiment concluded, as long as 145 days after treatment. Intrigued by this development, Nadler and his collaborators are conducting experiments to determine how long this reversal can be sustained and to uncover the biological mechanisms that are altered by the treatment.

Of course, what works in mice may not work in people, but the team’s decision to build its experiment around one drug that the FDA has already approved and another that has been well studied should speed the transition to clinical trials. Nadler’s work may also improve the outlook for Type 2 diabetics. Recent studies show that in addition to developing insulin resistance, Type 2 diabetics also are losing beta cells. This combination therapy could reverse that trend.

Cities on the Rebound

Follow the money. That’s one way of describing the approach that planning professors William Lucy and David Phillips are using to monitor the health of America’s cities and suburbs. Rather than rely on shifts in population, they look at shifts in income, and they found that cities are undergoing a steady resurgence. "Income captures the dynamics of a market economy," Lucy notes. "Tracking income tracks preferences in relation to opportunities."

Lucy and Phillips compared the performance of central cities to that of the entire metropolitan areas of which they are a part. Using newly released Census Bureau data from the American Community Survey, they found that between 2000 and 2004, per capita income in 22 cities rose 3 percentage points, to 89 percent of the average in their metropolitan areas.

Another encouraging trend: the median value of owner-occupied housing in cities increased nearly 3 percent, to 86.4 percent of overall metropolitan housing values, a number that actually understates the gain because city dwellings are typically smaller than those in the suburbs.

The professors point to a number of factors for this turnaround. With baby boomers reaching the empty-nest stage of life, a growing market for condominiums has emerged. Increasing commuter frustration with suburban traffic congestion has led more working adults to shorten their commutes by moving closer in.

While this is good news for most cities, the effects are not uniform across the country. Lucy notes that while the average per capita income in Atlanta was 128 percent of the metropolitan area average, in Detroit it was just 58 percent. Neighborhoods built between 1940 and 1970, when the average new house was between 1,000 and 1,400 square feet, tended to lag behind pre-1940 neighborhoods with larger houses that are closer to activities to which residents can walk.

Galactic Mergers and Acquisitions

One of the predictions of Albert Einstein’s theory of general relativity is the existence of gravitational waves, faint ripples in the space-time continuum caused by the explosively violent movement of enormous amounts of energy. In the 90 years since he published this theory, the existence of gravitational waves has been widely accepted, although no one has yet to observe them directly.

A computer simulation illustrates the powerful gravitational waves emitted by black holes as they spiral toward each other.

The latest discovery by Craig Sarazin, a U.Va. professor of astronomy, is about to change all this. "Scientists have long speculated that the collision of two supermassive black holes would be cataclysmic enough to produce gravitational waves," Sarazin explains. NASA is planning to launch a series of satellites called LISA, for Laser Interferometer Space Antenna, to observe them, but first the agency needs to be sure it could find supermassive black holes in the process of colliding.

Locating individual supermassive black holes is relatively easy. Most galaxies have them, and because they contain as much matter as 5 billion suns, they are hard to miss. But catching them in the act of colliding and combining proved surprisingly difficult.

"We found our pair by accident," Sarazin says. He was observing a cluster of galaxies using NASA’s Chandra X-ray Observatory, a logical choice since space in galaxy clusters is filled with gases that are so hot—more than 30 million degrees—that they produce X-rays, rather than light. The jets of plasma ejected from the accretion disk surrounding black holes are even hotter—reaching a trillion degrees—and Sarazin spotted two jets that were revolving around each other as their respective black holes moved together through space. "This braided contrail is evidence that these black holes are bound together and will ultimately merge," he says.

Although this particular set of black holes is not likely to collide for a million years or so, finding it is significant. Extrapolating from the particular circumstances surrounding this pair and multiplying them by the very large number of similar galaxies, scientists can now be confident that LISA will have something to look for.

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