Thirty years ago, the idea was put forth that a giant asteroid striking the Earth 65.5 million years ago led to the extinction of the dinosaurs and myriad other life forms on the planet. Other explanations were proposed that favored multiple asteroid impacts, massive volcanic eruptions or other precipitating events. Debate has been lively ever since.
In an effort to settle the matter, a team of 41 scientists from 12 nations reviewed an overwhelming amount of evidence and concluded that it was a single asteroid strike that set into motion giant earthquakes, tsunami surges more than 1,000 feet tall, and profound atmospheric changes that combined to make the planet uninhabitable for up to 70 percent of life forms. The finding appears in the journal Science.
Among experts weighing in: paleoceanographer Richard Norris, Ph.D., from Scripps Institution of Oceanography, who contributed evidence in sea-floor sediment records that indicate how deep-sea life was profoundly reshaped by the impact. (News release http://bit.ly/dnzGrX.)
Tracking during pregnancy
Many women are reluctant to use medications or receive vaccines during pregnancy out of fear about possible harm to their unborn child. But some medical conditions, such as asthma and influenza, if left untreated, can harm both the mother and her baby.
Researchers in the Department of Pediatrics at UCSD School of Medicine along with Boston University and the American Academy of Allergy, Asthma & Immunology have created the Vaccines and Medications in Pregnancy Surveillance System (VAMPSS) to provide information to pregnant women and their doctors about using medications and vaccines safely during pregnancy.
VAMPSS is designed to obtain comprehensive information on medicine and vaccine exposures from pregnant women or who have recently delivered, including those exposures that are unlikely to be included in the woman's medical record. For example, mothers are asked about all medicines taken, regardless of whether they were prescribed, over-the-counter, herbal products or borrowed from others. They are also asked about all vaccines they may have received, including those given in nontraditional settings such as health fairs or at the supermarket.
The goal is a more systematical way of information collection in order to evaluate risk and/or demonstrate the safety of a medication or vaccine during pregnancy. (News release
Treating esophageal disorder
Surgeons at UCSD Medical Center have performed the nation's first incision-free myotomy, a procedure to treat a disorder of the esophagus (known as achalasia), which causes difficulty swallowing, regurgitation and chest pain. The technique, performed through the patient's mouth with no external incisions, is the most recent in a series of clinical trial surgeries being evaluated by the UCSD Center for the Future of Surgery.
Heretofore, treating achalasia required a two-hour laparoscopic procedure requiring up to six small incisions in the abdomen to divide the esophageal muscle. The new incision-free technique is performed in less than 90 minutes. (Additional information at
Lynne Friedmann is a science writer based in Solana Beach.