Health & Science
A maximum limit to the human life span?
Many scientists believe that the first human who will live to the grand old age of 150 has already been born. Advances in medicine and sanitation have consistently pushed up the average life span over the past century, with a baby born today in the U.S. expected to live to 79, up from 50 in 1900. But a new study suggests that we have already hit our maximum longevity, and that life expectancy probably peaked in 1997 with the death of the world’s oldest person ever: 122-year-old Jeanne Calment of France. Geneticists at New York’s Albert Einstein College of Medicine analyzed two international databases on age and found that after decades of increases, the average maximum age plateaued in the mid-1990s, at just under 115. “We cannot break through that ceiling,” study leader Jan Vijg tells NPR.org. Describing Calment as an “outlier,” Vijg believes certain biological limits cannot be overcome by technological and medical advances. Our DNA and cells naturally accumulate damage over time, which eventually leads to the failure of crucial bodily functions. Rather than focus on lengthening life span, Vijg argues we should focus on extending our healthiest years through exercise, eating healthily, and perhaps taking drugs to fix some of the cellular damage. “There’s a good chance to improve health span,” he said. “That’s the most important thing.”
California’s mysterious fault line
The residents of Southern California live in constant fear of the “Big One,” a longoverdue devastating earthquake on the San Andreas Fault. Now seismologists may have discovered why they’ve been waiting so long. While conducting experiments in the Salton Sea, a lake near Palm Springs, a team of researchers found a previously unknown fault line running roughly parallel to the San Andreas Fault. They speculate that the Salton Trough Fault, which remained undetected because of its lack of seismic activity, may be absorbing some of the tectonic strain from its much larger neighbor—perhaps explaining why the southern section of the San Andreas Fault hasn’t produced a major earthquake for 300 years. The discovery doesn’t mean the Big One is any more or less likely. But by learning how these faults interact, geologists may be able to improve their earthquake modeling. “To aid in accurately assessing seismic hazard,” the study’s lead author, Valerie Sahakian, tells CSMonitor.com, “it is crucial to correctly identify and locate faults before earthquakes happen.”
The solar system’s new addition
Pluto has company. Astronomers from the University of Michigan have discovered another dwarf planet in the Kuiper Belt, the vast field of icy objects and debris that lies beyond Neptune in our solar system.
Known for now as 2014 UZ224, the Iowasize object is about half as big as Pluto, and almost twice as far from Earth—about 8.5 billion miles away. There are currently five recognized dwarf planets in the Milky Way—Pluto, Ceres, Eris, Haumea, and Makemake—but astronomers believe there could be at least 100 more. The latest discovery was made using a specially designed camera that maps far-flung galaxies. By studying the relatively still backdrop of distant star systems, the researchers were able to identify the subtle movements of closer bodies—including the new dwarf planet. They say their methods could help them track down “Planet Nine,” a hypothetical, massive planet thought to be hiding in the murky outer edges of the Milky Way. “The fact that we can find a very distant, very slow-moving object like this in our survey is a promising sign,” lead researcher David Gerdes tells The Washington Post. “If there are more things like this out there, we have a good shot at finding them.”
Astronauts’ ‘space brain’
Astronauts on a years-long trip to Mars may have more than just boredom to worry about: They could end up with “space brain.” One of NASA’s biggest concerns about taking humans to the Red Planet is the danger of excessive exposure to cosmic radiation, reports NBCNews.com. To investigate, researchers from the space agency exposed rats and mice to fully ionized oxygen and titanium particles, which are similar to the cosmic rays that would bombard astronauts on lengthy space flights. The rodents developed brain inflammation and other neural damage, and performed poorly on tests of memory and s learning—a condition researchers called “space brain.” Studies involving animals often fail to translate to people, but brain cancer patients who have received highdose, photon-based radiation treatment have developed similar cognitive problems. In another worrying sign, the radiationzapped rats and mice also displayed heightened levels of anxiety and stress. Such conditions, says study leader Charles Limoli, could reduce astronauts’ capability “to operate efficiently over the course of a deep space mission.” The only way to block out cosmic radiation is with more efficient shielding material, or an electromagnetic field to deflect the rays. NASA is exploring both options.
Health scare of the week
The toll of absent parents
Children who grow up without either their mother or their father are more likely to smoke or drink before they hit their teens, reports The Guardian (U.K.). British researchers examined data on nearly 11,000 children and their families. They found that kids who were separated from one parent in the first seven years of their life were more than twice as likely to have tried smoking by age 11 and nearly 1.5 times more likely to have drunk alcohol. It didn’t matter why the parent was missing— death, divorce, or otherwise—or whether it was the mother or father who was absent. The study’s authors speculate that these children may be adopting unhealthy coping strategies to deal with painful family issues. “Significant changes early in life are already known to have an impact on a child’s development, their later health, and risky behaviors,” says Russell Viner from the Royal College of Pediatrics and Child Health in London. “We need to do everything we can to put our children onto trajectories towards positive health.”