Researchers have begun to zero in on genes that might be responsible for autism.

NOVA is produced by WGBH in Boston. National corporate funding for NOVA is provided by The Boeing Company. Major funding for NOVA is provided by David H. Koch, the Corporation for Public Broadcasting, and PBS viewers.

Funding for NOVA scienceNOW is provided by the National Science Foundation, the Alfred P. Sloan Foundation, and PBS viewers.

This material is based upon work supported by the National Science Foundation under Grant No. 0407101. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the National Science Foundation.

If you were a spy, how could you ensure that an encrypted message got safely to your allies? Send it using entangled particles! Here, watch how a technique called quantum cryptography could save a state secret from falling into enemy hands.

Major funding for "The Fabric of the Cosmos" is provided by the National Science Foundation.

Additional funding for this program is provided by the Arthur Vining Davis Foundations.

National corporate funding for NOVA is provided by The Boeing Company. Major funding for NOVA is provided by David H. Koch, the Corporation for Public Broadcasting, and PBS viewers.

Water buffalo tusks, fish bladders, and animal sinew all went into the making of the ancient Egyptian composite bow. While the materials may seem primitive, this powerful weapon was not so different from the bows of today.

NOVA is produced by WGBH in Boston. National corporate funding for NOVA is provided by The Boeing Company. Major funding for NOVA is provided by David H. Koch, the Corporation for Public Broadcasting, and PBS viewers.

A computer scientist finds novel ways to stop spammers and harness the brainpower of millions of people.

NOVA is produced by WGBH in Boston. Funding for NOVA scienceNOW is provided by the National Science Foundation, the Alfred P. Sloan Foundation, and PBS viewers.

National corporate funding for NOVA is provided by The Boeing Company. Major funding for NOVA is provided by David H. Koch, the Corporation for Public Broadcasting, and PBS viewers.

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This material is based upon work supported by the National Science Foundation under Grant No. 0407101. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the National Science Foundation.

Three separate teams overcome a biomedical hurdle-creating stem cells without the use of human embryos.

NOVA is produced by WGBH in Boston. Funding for NOVA scienceNOW is provided by the National Science Foundation, the Alfred P. Sloan Foundation, and PBS viewers.

National corporate funding for NOVA is provided by The Boeing Company. Major funding for NOVA is provided by David H. Koch, the Corporation for Public Broadcasting, and PBS viewers.

This material is based upon work supported by the National Science Foundation under Grant No. 0407101. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the National Science Foundation.

It used to be standard practice that all patients received chemotherapy after surgery to prevent the recurrence of breast cancer. Today, a genetic test called Oncotype DX allows doctors to analyze the genome of a patient's cancer cells. The results can help oncologists determine whether a patient actually needs to endure chemotherapy post-surgery, thereby avoiding needless suffering.

NOVA is produced by WGBH in Boston. National corporate funding for NOVA is provided by The Boeing Company. Major funding for NOVA is provided by David H. Koch, the Corporation for Public Broadcasting, and PBS viewers.

Knocks to the head may seem funny in cartoons, sports replays, and YouTube videos, but even minor head injuries often lead to serious concussions. A concussion may leave no trace on a conventional MRI scan yet cause permanent memory loss, attention problems, and depression. NOVA scienceNOW investigates promising new leads in understanding this puzzling condition, which affects millions of people in the U.S., including many high-school and college athletes who suffer concussions yet are encouraged to return to the playing field.

NOVA is produced by WGBH in Boston. Funding for NOVA scienceNOW is provided by the National Science Foundation, the Alfred P. Sloan Foundation, and PBS viewers.

National corporate funding for NOVA is provided by The Boeing Company. Major funding for NOVA is provided by David H. Koch, the Corporation for Public Broadcasting, and PBS viewers.

This material is based upon work supported by the National Science Foundation under Grant No. 0407101. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the National Science Foundation.

Custom-made hearts, lungs, kidneys, and other organs could revolutionize organ transplantation.

NOVA is produced by WGBH in Boston. Funding for NOVA scienceNOW is provided by the National Science Foundation, the Alfred P. Sloan Foundation, and PBS viewers.

National corporate funding for NOVA is provided by The Boeing Company. Major funding for NOVA is provided by David H. Koch, the Corporation for Public Broadcasting, and PBS viewers.

See how "exercise in a pill" could one day help the elderly and the bedridden.

For more, visit pbs.org/sciencenow

NOVA is produced by WGBH in Boston. Funding for NOVA scienceNOW is provided by the National Science Foundation, the Alfred P. Sloan Foundation, and PBS viewers.

National corporate funding for NOVA is provided by The Boeing Company. Major funding for NOVA is provided by David H. Koch, the Corporation for Public Broadcasting, and PBS viewers.

This material is based upon work supported by the National Science Foundation under Grant No. 0407101. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the National Science Foundation.

Thousands of people are signing up to post their DNA sequences on the Internet, for all to see. Are they crazy?

Funding for NOVA scienceNOW is provided by the National Science Foundation, the Alfred P. Sloan Foundation, and PBS viewers.

NOVA is produced by WGBH in Boston. National corporate funding for NOVA is provided by The Boeing Company. Major funding for NOVA is provided by David H. Koch, the Corporation for Public Broadcasting, and PBS viewers.

This material is based upon work supported by the National Science Foundation under Grant No. 0407101. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the National Science Foundation.