Three years ago Mark Kay, MD, PhD, published the first results showing that a biological phenomenon called RNA interference could be an effective gene therapy technique. Since then he has used RNAi gene therapy to effectively shut down the viruses that cause hepatitis and HIV in mice.

With three human RNAi gene therapy trials now under way - two in macular degeneration and one in RSV pneumonia - the technique Kay pioneered may be among the first to find widespread use for treating human diseases.

Three hundred million years ago, Earth's climate shifted dramatically from icehouse to hothouse, with major environmental consequences. That shift was the result of both rising atmospheric carbon dioxide concentrations and the melting of vast ice sheets, new research by University of Michigan paleoclimatologist Christopher Poulsen shows.

Poulsen will discuss his findings in a symposium titled "Geosystems: Climate Lessons from Earth's Last Great Icehouse" at the annual meeting of the American Association for the Advancement of Science in San Francisco.

The changes occurred during the period of Earth's history when the continents were consolidated into a single supercontinent, Pangaea.

As NASA develops its next "flagship" mission to the outer solar system, Jupiter's enigmatic moon Europa should be the target, says Arizona State University professor Ronald Greeley. Although Europa lies five times farther from the Sun than Earth, he notes it may offer a home for life.

Greeley, a Regents' Professor, heads the Planetary Geology Group in ASU's School of Earth and Space Exploration. He is presenting the Europa proposal today (Feb. 18) at the annual meeting of the American Association for the Advancement of Science in San Francisco.

"Europa is unique in our solar system," says Greeley. "It's a rocky object a little smaller than our Moon, and it's covered with a layer of water 100 miles deep." This holds more water than all the oceans on Earth, he explains.

The American Association for the Advancement of Science (AAAS) today released a new video as well as the first consensus statement of its board of directors regarding global climate change during a free public town hall meeting in San Francisco, California.

The town hall meeting, part of the 2007 AAAS Annual Meeting, was organized by AAAS in collaboration with three leading U.S. education organizations -- the California Science Teachers Association, the National Science Teachers Association, and the United Educators of San Francisco (representing the National Education Association and the American Federation of Teachers).

In almost all forms of heart failure, the heart begins to express genes that are normally only expressed in the fetal heart. Researchers have known for years that this fetal-gene reactivation happens, yet not what regulates it. Now, investigators at the University of Pennsylvania School of Medicine have discovered that an enzyme important in fetal heart-cell development regulates the enlargement of heart cells, known as cardiac hypertrophy, which is a precursor to many forms of congestive heart failure (CHF).

The safest possible future for advancing nanotechnology in a sustainable world can be reached by using green chemistry, says James E. Hutchison, a professor of chemistry at the University of Oregon.

“Around the world, there is a growing urgency about nanotechnology and its possible health and environmental impacts,” Hutchison said in his talk Sunday during a workshop at the annual meeting of the American Association for the Advancement of Science. “There is a concern that these issues will hinder commercialization of this industry.”

Scientists need to take a proactive approach to advancing from the current discovery phase in the creation of nanomaterials into a production phase that is efficient and reduces waste, he said.